出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/03/06 03:36:18」(JST)
この項目では、コンピュータのプログラムについて説明しています。
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ライブラリ（Library）は、汎用性の高い複数のプログラムを、再利用可能な形でひとまとまりにしたものである。一般にライブラリは、それ単体ではプログラムとして動作させることはできないので実行ファイルではない。ライブラリは他のプログラムに何らかの機能を提供するコードの集まりと言うことができる。ソースコードの場合と、オブジェクトコード、あるいは専用の形式を用いる場合とがある。たとえば、UNIXのライブラリはオブジェクトコードをarと呼ばれるアーカイバでひとまとめにして利用する。
また、ソフトウェア以外の再利用可能なものの集合について使われることもある。
動的リンク (dynamic linking)は、あるライブラリ内のデータ（コードを含む）を新たな実行ファイルのコンパイル時にコピーすることはなく、ディスク上に別のファイルとして存在している。コンパイル時にリンカが行うのは、その実行ファイルが必要とするのがどのライブラリのどの部分であるか（関数名やインデックス）を記録するだけである。リンク作業の大部分はそのアプリケーションがメモリ上にロードされたときか、実行時である。リンクを行うコードはローダ（loader）と呼ばれ、実際にはオペレーティングシステム (OS)の一部と見なされる。適当な時点でローダは必要なライブラリをディスク上で見つけてプロセスのメモリ空間に（追加のデータ空間と共に）マッピングする。OSによってはプロセスが実行開始する前でないとライブラリをリンクできないものもあるが、多くのOSではプロセス実行時に実際にライブラリを参照したときにリンクすることができる。後者は「遅延読み込み」などと呼ばれる。どちらの場合もライブラリはダイナミックリンクライブラリ、共有ライブラリ、シェアードライブラリなどと呼ばれる。DLL という呼び方は Microsoft Windows 環境で一般的であり、動的ライブラリのファイル拡張子は .dll である。
ローダの処理は、メモリ上の各ライブラリの位置が実際にロードされるまで確定しないため、ちょっとしたトリックを必要とする。ディスク上のファイル内に絶対アドレスを書きこんでおくことはDLL内であっても不可能である。理論的にはメモリにロードされたときにライブラリを参照している部分を全て書き換えて正しいメモリ上の位置を参照するようにすることはできるが、それによって消費される時間とメモリは無視できない。その代わりに多くの動的リンクシステムではアドレス欄が空欄となったシンボルテーブルをコンパイル時に用意する。ライブラリへの参照は全てこのシンボルテーブルを経由して行われる（コンパイラはシンボルテーブルからアドレスを取り出して使うコードを生成する）。メモリにロードされたとき、ローダがこのテーブルを書き換える。
ライブラリも全メソッド（関数、サブルーチン）のテーブルを持っている。ライブラリに入ってくるときは、このテーブルを経由して各ルーチンにジャンプする。これによってライブラリのルーチンコールにオーバヘッドが発生するが、それは無視できるほど小さい。
動的リンカ・ローダは機能面で様々なものがある。いくつかの場合、実行ファイルに格納された明示的なライブラリパスに依存し、ライブラリ名やディスク上の配置を変更するとシステムが動作できなくなる。より一般的な手法としてはライブラリ名だけを実行ファイルに格納し、オペレーティングシステムが何らかのアルゴリズムでディスク上のライブラリを検索する。UNIX系システムでは、ライブラリを探す場所（ディレクトリ）を構成ファイルにリストアップしておく。ライブラリ開発者はそこに書かれたディレクトリにライブラリを配置することを推奨される。しかし、この方法では新しいライブラリをインストールする際に問題が発生しやすく、共通のディレクトリにあまりにも多くのライブラリが置かれることとなって管理を難しくする。Microsoft Windows ではレジストリを使ってActiveX DLL の場所を決めているが、標準DLLでは、
で示されるディレクトリを探す（古いバージョンではカレントディレクトリが2番目だった）[1]。OPENSTEPはもっと柔軟なシステムを使用していて、ライブラリの探索リストを保持している。しかし不正なDLLが探索の上位に置かれていると実行ファイルは不正動作する可能性がある。Windowsでは、これが「DLL地獄」（DLL hell）と呼ばれ、よく知られている問題である。
Windows XPからは、Side-by-Sideアセンブリ (DLL署名, WinSxS)というメカニズムが追加された。これは動的リンク時にライブラリのファイル名ではなく、ライブラリにつけられた署名によってリンクすべきライブラリを決定するものである。これにより、同じファイル名を持つが異なる実装を持つライブラリを同時に使い分ける事ができる。よくあるパターンとして、ソースコードから改変・ビルドされたランタイムライブラリをシステムにインストールする場合にこのメカニズムが有効に働く。システムにインストールされたライブラリはライブラリ探索リスト上比較的上位に存在するが、署名が一致するプログラムにのみロードされるのでDLL地獄は今後解消されるであろうと考えられる。しかし、この機構には一つの弱点がある。それはシステムライブラリをオーバーライドして独自機能を実装する時、この機構は役に立たない方向へ働く。その様な実装をする時には、故意にマニフェスト機能を無効にしてライブラリを作らなくてはならない。もっとも、そのようなアプローチは、システムファイル保護機能が搭載されたWindows 2000のリリース時点で時代遅れであり、Windows Vistaに至っては管理者と言えどもシステムライブラリを書き換える事は出来なくなっている。
動的ライブラリの起源は定かではないが、少なくとも1960年代後半のMTS (Michigan Terminal System)まで遡ることができる("A History of MTS", Information Technology Digest, Vol. 5, No. 5)。
これは動的リンクの下位カテゴリであり、コンパイル時にリンクされた以外のダイナミックリンクライブラリを実行中のプログラムが明示的にロードすることである。この場合、ライブラリはプラグインモジュールとして使われるのが一般的で、表計算プログラムのadd-inや特定機能を実現するインタプリタなどが典型的である。
動的ライブラリをサポートしているシステムは動的読み込みAPIもサポートしているのが一般的である。例えばWindowsは LoadLibrary() と GetProcAddress() を用意していて、UNIX系システムでは dlopen() と dlsym() を用意している。いくつかの開発システムではこの処理を自動化している。
もうひとつのライブラリの形態として完全に分離された実行ファイルをRPCと呼ばれる方法で接続するものがある。このアプローチではオペレーティングシステムの再利用が最大に生かされる。つまり、ライブラリサポートのためのコードはアプリケーションサポートのコードやセキュリティサポートのコードと共通化できる。さらに、このライブラリはネットワークを経由した別のマシン上に存在しても構わない。
欠点はライブラリコールの度に無視できないオーバヘッドが発生することである。RPCは非常にコストがかかり、可能な限り排除されてきた。しかし、このアプローチは特定分野で一般化しつつある。特にクライアントサーバシステムやEnterprise JavaBeansのようなアプリケーションサーバで一般的である。
動的か静的かとは別に、ライブラリはプログラム間で共有される方式でも分類される。動的ライブラリは何らかの共有をサポートしており、複数のプログラムが同時に同じライブラリを使用することができる。静的ライブラリは各プログラムにリンクされるため、共有することはできない。
共有ライブラリ (shared library)は、やや曖昧な用語であり、ふたつの概念を含む。第一はディスク上のコードを複数の無関係なプログラムが共有することを意味する。第二の概念はメモリ上のコードの共有であり、ライブラリのロードされた物理メモリページが複数のプロセスのアドレス空間にマップされ、同時にアクセスされることを意味する。一般に後者を共有ライブラリと称するのが推奨され、この方式には様々な利点がある。例えばOPENSTEPでは、アプリケーションの多くは数百Kバイトで即座にロード可能であり、その機能の大部分はライブラリ上に実装されていて、共有可能であるためにOSが別のプログラム用にメモリにロードしたコードイメージがそのまま使用できる。しかし、マルチタスク環境で共有されるコードは特別な配慮が必要であり、そのために性能が若干低下する。
メモリ上の共有ライブラリはUNIXでは位置独立コード (PIC) を使って実現される。これは柔軟なアーキテクチャだが複雑であり、Windowsなどでは使われていない。Windowsなどは、DLL毎にマップすべきアドレスを事前に決めておくなどしてメモリ上で共有可能にしている。WindowsのDLLはUNIXから見れば共有ライブラリではない。（訳注：UNIXでもライブラリのマップすべきアドレスを決めている場合がある。ただしそれは性能向上目的であり、基本的にはPIC化されている。）
最近のOSでは共有ライブラリは通常の実行ファイルと同じ形式になっている。これにはふたつの利点がある。第一はひとつのローダで両方をロードできる。それによってローダが若干複雑化するが、十分コストに見合う程度である。第二はシンボルテーブルさえあれば実行ファイルを共有ライブラリとして使うことができる点である。このようなファイル形式として、ELF (UNIX)と PE (Windows)がある。また、Windowsではフォントなどのリソースも同じファイル形式になっている。OPENSTEPでもほとんど全てのシステムリソースが同じファイル形式になっている。
DLLという用語はWindowsやOS/2で主に使われる。UNIXでは「共有ライブラリ」が一般的である。
マルチスレッド環境下でライブラリを使用するにあたっては、別の共有問題が発生する。ライブラリルーチンがデータ領域としてスタックのみを使う場合は問題ないが、ライブラリ内のデータ領域を使う場合、そのデータ領域がスレッド毎に用意されていないことが多い。したがって、そのようなライブラリルーチンを使う場合、実行ファイル側で同時に複数のスレッドが同じライブラリルーチンを使わないように注意しなければならないことがある。
1980年代終盤に開発された動的リンクは1990年代初期にはほとんどのオペレーティングシステムで使用可能となった。ほぼ同時期にオブジェクト指向プログラミング (OOP)が市場に出回り始めた。OOP は従来のライブラリが提供していなかった情報を必要とした。それは、あるオブジェクトが依存しているオブジェクトのリストである。これはOOPの継承という機能の副作用であり、あるメソッドの完全な定義は複数の場所に分散して配置される可能性がある。これは単純化すればライブラリ間の依存関係ということになるが、真のOOPシステムではコンパイル時には依存関係が明らかでなく、そのために様々な解決方法が登場した。
同じころ、多層構造のシステムの考え方も出てきた。デスクトップコンピュータ上の表示プログラムが汎用コンピュータやミニコンピュータの記憶装置や演算機能を利用するものである。例えばGUIベースのコンピュータがミニコンピュータにメッセージを送り、表示すべき膨大なデータの一部を得るというものが考えられた。RPCは既に使われていたが、それは標準化されていなかった。
主要なミニコンおよび汎用機メーカーがこれら二つの問題に関してプロジェクトを結成し、どこでも使えるOOPライブラリ形式を開発した。このようなシステムをオブジェクト・ライブラリ (object library)と呼んだり、リモートアクセスが可能ならば分散オブジェクト (distributed objects)と呼ぶ。マイクロソフト社のCOMは分散機能のないオブジェクトライブラリであり、DCOMはリモートアクセスを可能としたバージョンである。
一時期、オブジェクトライブラリはプログラミングの世界の「次の大きな出来事」とされた。様々なシステムが開発され、競争も激化した。例をあげると、IBMのSOM/DSOM、サン・マイクロシステムズのDOE、NeXTのPDO、DECの ObjectBroker、マイクロソフトのComponent Object Model (COM/DCOM)、そして様々なCORBAベースのシステムがある。
結局、OOPライブラリは次の大きな出来事ではなかった。マイクロソフトのCOMとNeXT（現在はアップル）のPDO以外は、ほとんど使われることも無くなったのである。
Javaではオブジェクトライブラリとして主にjarが使われている。その中には（圧縮された）クラスのバイトコード形式が格納されていて、Java-VMや特殊なクラスローダがそれをロードする。
/lib、/usr/lib、/usr/local/lib などのフォルダに置かれる libfoo.a や libfoo.so といったファイルはダイナミックリンクライブラリである。ファイル名は常に lib で始まり、.a（静的ライブラリ）か .so（ダイナミックリンクライブラリ）で終わる。オプションとしてインターフェイス番号が付与される場合がある。例えば、libfoo.so.2 は libfoo ライブラリの二番目のメジャーなインターフェイス番号の付いたダイナミックリンクライブラリである。古いUNIXではマイナー番号も使っている場合がある (libfoo.so.1.2)が、最近のUNIXではメジャー番号しか使っていない。動的にロードされたライブラリは /usr/libexec などのディレクトリに置かれる。ライブラリのディレクトリにある .la ファイルは libtool アーカイブである。.dylib の代わりに .so を使うことも出来る。しかし、多くの動的ライブラリは「バンドル」 (bundles)と呼ばれる特別な場所に置かれ、ライブラリに関連するファイルやメタデータもそこに置かれる。例えば、"My Neat Library" というライブラリは "My Neat Library.framework" というバンドルに実装される。*.LIB というファイルは静的ライブラリで、*.DLL というファイルはダイナミックリンクライブラリである。インターフェイスのリビジョンはファイル内に書きこまれるか、COMインターフェイスを使って抽象化される。また、.NET アセンブリについては、内部のマニフェストに記述される。
A library is an organized collection of sources of information and similar resources, made accessible to a defined community for reference or borrowing. It provides physical or digital access to material, and may be a physical building or room, or a virtual space, or both.[1] A library's collection can include books, periodicals, newspapers, manuscripts, films, maps, prints, documents, microform, CDs, cassettes, videotapes, DVDs, Blu-ray Discs, e-books, audiobooks, databases, and other formats. Libraries range in size from a few shelves of books to several million items. In Latin and Greek, the idea of bookcase is represented by Bibliotheca and Bibliothēkē (Greek: βιβλιοθήκη): derivatives of these mean library in many modern languages, e.g. French bibliothèque.
The first libraries consisted of archives of the earliest form of writing—the clay tablets in cuneiform script discovered in Sumer, some dating back to 2600 BC. These written archives mark the end of prehistory and the start of history. The earliest discovered private archives were kept at Ugarit. There is also evidence of libraries at Nippur about 1900 BC and at Nineveh about 700 BC showing a library classification system. Private or personal libraries made up of written books (as opposed to the state or institutional records kept in archives) appeared in classical Greece in the 5th century BC. In the 6th century, at the very close of the Classical period, the great libraries of the Mediterranean world remained those of Constantinople and Alexandria. From the 15th century in central and northern Italy, libraries of humanists and their enlightened patrons provided a nucleus around which an "academy" of scholars congregated in each Italian city of consequence. Tianyi Chamber, founded in 1561 by Fan Qin during the Ming Dynasty, is the oldest existing library in China. In its heyday it boasted a collection of 70,000 volumes of antique books. The first library classification system was set up during the Han Dynasty. In North America, it is believed that personal collections of books were brought over to the continent by French settlers in the 16th century. The oldest non-personal library on the North American continent was founded at the Jesuit College in Quebec City in 1635. The first textbook on library science was written by Martin Schrettinger and published in 1808.[2]
A library is organized for use and maintained by a public body, an institution, a corporation, or a private individual. Public and institutional collections and services may be intended for use by people who choose not to—or cannot afford to—purchase an extensive collection themselves, who need material no individual can reasonably be expected to have, or who require professional assistance with their research. In addition to providing materials, libraries also provide the services of librarians who are experts at finding and organizing information and at interpreting information needs. Libraries often provide quiet areas for studying, and they also often offer common areas to facilitate group study and collaboration. Libraries often provide public facilities for access to their electronic resources and the Internet. Modern libraries are increasingly being redefined as places to get unrestricted access to information in many formats and from many sources. They are extending services beyond the physical walls of a building, by providing material accessible by electronic means, and by providing the assistance of librarians in navigating and analyzing very large amounts of information with a variety of digital tools.
The first libraries consisted of archives of the earliest form of writing—the clay tablets in cuneiform script discovered in temple rooms in Sumer,[3][4] some dating back to 2600 BC.[5] These archives, which mainly consisted of the records of commercial transactions or inventories, mark the end of prehistory and the start of history.[6][7]
Things were much the same in the government and temple records on papyrus of Ancient Egypt.[4] The earliest discovered private archives were kept at Ugarit; besides correspondence and inventories, texts of myths may have been standardized practice-texts for teaching new scribes. There is also evidence of libraries at Nippur about 1900 BC and those at Nineveh about 700 BC showing a library classification system.[8]
Over 30,000 clay tablets from the Library of Ashurbanipal have been discovered at Nineveh,[9] providing modern scholars with an amazing wealth of Mesopotamian literary, religious and administrative work. Among the findings were the Enuma Elish, also known as the Epic of Creation,[10] which depicts a traditional Babylonian view of creation, the Epic of Gilgamesh,[11] a large selection of "omen texts" including Enuma Anu Enlil which "contained omens dealing with the moon, its visibility, eclipses, and conjunction with planets and fixed stars, the sun, its corona, spots, and eclipses, the weather, namely lightning, thunder, and clouds, and the planets and their visibility, appearance, and stations",[12] and astronomic/astrological texts, as well as standard lists used by scribes and scholars such as word lists, bilingual vocabularies, lists of signs and synonyms, and lists of medical diagnoses.
Philosopher Laozi was keeper of books in the earliest library in China, which belonged to the Imperial Zhou dynasty.[13] Also, evidence of catalogues found in some destroyed ancient libraries illustrates the presence of librarians.[13]
The Library of Alexandria, in Egypt, was the largest and most significant great library of the ancient world.[14] It flourished under the patronage of the Ptolemaic dynasty and functioned as a major center of scholarship from its construction in the 3rd century BC until the Roman conquest of Egypt in 30 BC. The library was conceived and opened either during the reign of Ptolemy I Soter (323–283 BC) or during the reign of his son Ptolemy II (283–246 BC).[15] An early organization system was in effect at Alexandria.[15]
The Library of Celsus in Ephesus, Anatolia, now part of Selçuk, Turkey was built in honor of the Roman Senator Tiberius Julius Celsus Polemaeanus[16][17] (completed in 135 AD) by Celsus’ son, Gaius Julius Aquila (consul, 110 AD). The library was built to store 12,000 scrolls and to serve as a monumental tomb for Celsus.
Private or personal libraries made up of written books (as opposed to the state or institutional records kept in archives) appeared in classical Greece in the 5th century BC. The celebrated book collectors of Hellenistic Antiquity were listed in the late 2nd century in Deipnosophistae. All these libraries were Greek; the cultivated Hellenized diners in Deipnosophistae pass over the libraries of Rome in silence. By the time of Augustus there were public libraries near the forums of Rome: there were libraries in the Porticus Octaviae near the Theatre of Marcellus, in the temple of Apollo Palatinus, and in the Bibliotheca Ulpiana in the Forum of Trajan. The state archives were kept in a structure on the slope between the Roman Forum and the Capitoline Hill.
Private libraries appeared during the late republic: Seneca inveighed against libraries fitted out for show by illiterate owners who scarcely read their titles in the course of a lifetime, but displayed the scrolls in bookcases (armaria) of citrus wood inlaid with ivory that ran right to the ceiling: "by now, like bathrooms and hot water, a library is got up as standard equipment for a fine house (domus).[18] Libraries were amenities suited to a villa, such as Cicero's at Tusculum, Maecenas's several villas, or Pliny the Younger's, all described in surviving letters. At the Villa of the Papyri at Herculaneum, apparently the villa of Caesar's father-in-law, the Greek library has been partly preserved in volcanic ash; archaeologists speculate that a Latin library, kept separate from the Greek one, may await discovery at the site.
In the West, the first public libraries were established under the Roman Empire as each succeeding emperor strove to open one or many which outshone that of his predecessor. Rome’s first public library was established by Asinius Pollio. Pollio was a lieutenant of Julius Caesar and one of his most ardent supporters. After his military victory in Illyria, Pollio felt he had enough fame and fortune to create what Julius Caesar had sought for a long time: a public library to increase the prestige of Rome and rival the one in Alexandria.[19] Pollios’s library, the Anla Libertatis,[20] which was housed in the Atrium Libertatis, was centrally located near the Forum Romanum. It was the first to employ an architectural design that separated works into Greek and Latin. All subsequent Roman public libraries will have this design.[21] At the conclusion of Rome’s civil wars following the death of Marcus Antonius in 30 BC, the Emperor Augustus sought to reconstruct many of Rome’s damaged buildings. During this construction, Augustus created two more public libraries. The first was the library of the Temple of Apollo on the Palatine, often called the Palatine library, and the second was the library of the Porticus of Octaviae[22]
Two more libraries were added by the Emperor Tiberius on Palatine Hill and one by Vespasian after 70 AD. Vespasian’s library was constructed in the Forum of Vespasian, also known as the Forum of Peace, and became one of Rome’s principal libraries. The Bibliotheca Pacis was built along the traditional model and had two large halls with rooms for Greek and Latin libraries containing the works of Galen and Lucius Aelius.[23] One of the best preserved was the ancient Ulpian Library built by the Emperor Trajan. Completed in 112/113 AD, the Ulpian Library was part of Trajan’s Forum built on the Capitoline Hill. Trajan’s Column separated the Greek and Latin rooms which faced each other.[24] The structure was approximately fifty feet high with the peak of the roof reaching almost seventy feet.[25]
Unlike the Greek libraries, readers had direct access to the scrolls, which were kept on shelves built into the walls of a large room. Reading or copying was normally done in the room itself. The surviving records give only a few instances of lending features. Most of the large Roman baths were also cultural centres, built from the start with a library, a two room arrangement with one room for Greek and one for Latin texts.
Libraries were filled with parchment scrolls as at Library of Pergamum and on papyrus scrolls as at Alexandria: the export of prepared writing materials was a staple of commerce. There were a few institutional or royal libraries which were open to an educated public (such as the Serapeum collection of the Library of Alexandria, once the largest library in the ancient world),[15] but on the whole collections were private. In those rare cases where it was possible for a scholar to consult library books there seems to have been no direct access to the stacks. In all recorded cases the books were kept in a relatively small room where the staff went to get them for the readers, who had to consult them in an adjoining hall or covered walkway.
Han Chinese scholar Liu Xiang established the first library classification system during the Han Dynasty,[26] and the first book notation system. At this time the library catalogue was written on scrolls of fine silk and stored in silk bags.
During the Late Antiquity and Middle Ages periods, there was no Rome of the kind that ruled the Mediterranean for centuries and spawned the culture that produced twenty-eight public libraries in the urbs Roma.[28] The empire had been divided then later re-united again under Constantine the Great who moved the capital of the Roman Empire in 330 AD to the city of Byzantium which was renamed Constantinople.[29] The Roman intellectual culture that flourished in ancient times was undergoing a transformation as the academic world moved from laymen to Christian clergy.[30] As the West crumbled, books and libraries flourished and flowed east toward the Byzantine Empire.[31] There, four different types of libraries were established: imperial, patriarchal, monastic, and private.[32] Each had it own purpose and, as a result, their survival varied.
Christianity was a new force in Europe and many of the faithful saw Hellenistic culture as pagan. As such, many classical Greek works, written on scrolls, were left to decay as only Christian texts were thought fit for preservation in a codex, the progenitor of the modern book.[33] In the East, however, this was not the case as many of these classical Greek and Roman texts were copied.[34]
In Byzantium, much of this work devoted to preserving Hellenistic thought in codex form was performed in scriptoriums by monks.[35] While monastic library scriptoriums flourished throughout the East and West, the rules governing them were generally the same [36] Barren and sun-lit rooms (because candles were a source of fire) were major features of the scriptorium that was both a model of production and monastic piety.[37] Monks scribbled away for hours a day, interrupted only by meals and prayers.[38] With such production, medieval monasteries began to accumulate large libraries. These libraries were devoted solely to the education of the monks and were seen as essential to their spiritual development.[39] Although most of these texts that were produced were Christian in nature, many monastic leaders saw common virtues in the Greek classics. As a result, many of these Greek works were copied, and thus saved, in monastic scriptoriums.[40]
When Europe passed into the Dark Ages, Byzantine scriptoriums laboriously preserved Greco-Roman classics. As a result, Byzantium revived Classical models of education and libraries.[41] The Imperial Library of Constantinople was an important depository of ancient knowledge. Constantine himself wanted such a library but his short rule denied him the ability to see his vision to fruition. His son Constantius II made this dream a reality and created an imperial library in a portico of the royal palace.[42] He ruled for 24 years and accelerated the development of the library and the intellectual culture that came with such a vast accumulation of books.[43]
Constantius II appointed Themistius, a pagan philosopher and teacher, as chief architect of this library building program. Themistius set about a bold program to create an imperial public library that would be the centerpiece of the new intellectual capital of Constantinople.[44] Classical authors such as Plato, Aristotle, Demosthenes, Isocrates, Thucydides, Homer, and Zeno were sought. Themeistius hired calligraphers and craftsman to produce the actual codices. He also appointed educators and created a university-like school centered around the library.[45]
After the death of Constantius II, Julian the Apostate, a bibliophile intellectual, ruled briefly for less than three years. Despite this, he had a profound impact on the imperial library and sought both Christian and pagan books for its collections.[42] Later, the Emperor Valens hired Greek and Latin scribes full-time with from the royal treasury to copy and repair manuscripts.[46]
At its height in the 5th century, the Imperial Library of Constantinople had 120,000 volumes and was the largest library in Europe.[47] A fire in 477 consumed the entire library but it was rebuilt only to be burned again in 726, 1204, and in 1453 when Constantinople fell to the Ottoman Turks.[48]
Patriarchal libraries fared no better, and sometimes worse, than the Imperial Library. The Library of the Patriarchate of Constantinople was founded most likely during the reign of Constantine the Great in the 4th century.[49] As a theological library, it was known to have employed a library classification system.[50] It also served as a repository of several ecumenical councils such as the Council of Nicea, Council of Ephesus, and the Council of Chalcedon. The library, which employed a librarian and assistants, may have been originally located in the Patriarch’s official residence before it was moved to the Thomaites Triclinus in the 7th century. While much is not known about the actual library itself, it is known that many of its contents were subject to destruction as religious in-fighting ultimately resulted in book burnings.[51]
During this period, small private libraries existed. Many of these were owned by church members and the aristocracy.[52] Teachers also were known to have small personal libraries as well as wealthy bibliophiles who could afford the highly ornate books of the period.[53]
Thus, in the 6th century, at the close of the Classical period, the great libraries of the Mediterranean world remained those of Constantinople and Alexandria. Cassiodorus, minister to Theodoric, established a monastery at Vivarium in the toe of Italy (modern Calabria) with a library where he attempted to bring Greek learning to Latin readers and preserve texts both sacred and secular for future generations. As its unofficial librarian, Cassiodorus not only collected as many manuscripts as he could, he also wrote treatises aimed at instructing his monks in the proper uses of reading and methods for copying texts accurately. In the end, however, the library at Vivarium was dispersed and lost within a century.
Through Origen and especially the scholarly presbyter Pamphilus of Caesarea, an avid collector of books of Scripture, the theological school of Caesarea won a reputation for having the most extensive ecclesiastical library of the time, containing more than 30,000 manuscripts: Gregory Nazianzus, Basil the Great, Jerome and others came and studied there.
By the 8th century first Iranians and then Arabs had imported the craft of papermaking from China, with a paper mill already at work in Baghdad in 794. By the 9th century public libraries started to appear in many Islamic cities. They were called "halls of Science" or dar al-'ilm. They were each endowed by Islamic sects with the purpose of representing their tenets as well as promoting the dissemination of secular knowledge. The 9th-century Abbasid Caliph al-Mutawakkil of Iraq, ordered the construction of a "zawiyat qurra" – an enclosure for readers which was "lavishly furnished and equipped". In Shiraz Adhud al-Daula (d. 983) set up a library, described by the medieval historian, al-Muqaddasi, as "a complex of buildings surrounded by gardens with lakes and waterways. The buildings were topped with domes, and comprised an upper and a lower story with a total, according to the chief official, of 360 rooms.... In each department, catalogues were placed on a shelf... the rooms were furnished with carpets".[54] The libraries often employed translators and copyists in large numbers, in order to render into Arabic the bulk of the available Persian, Greek, Roman and Sanskrit non-fiction and the classics of literature. This flowering of Islamic learning ceased centuries later when learning began declining in the Islamic world, after many of these libraries were destroyed by Mongol invasions. Others were victim of wars and religious strife in the Islamic world. However, a few examples of these medieval libraries, such as the libraries of Chinguetti in West Africa, remain intact and relatively unchanged. Another ancient library from this period which is still operational and expanding is the Central Library of Astan Quds Razavi in the Iranian city of Mashhad, which has been operating for more than six centuries.
The contents of these Islamic libraries were copied by Christian monks in Muslim/Christian border areas, particularly Spain and Sicily. From there they eventually made their way into other parts of Christian Europe. These copies joined works that had been preserved directly by Christian monks from Greek and Roman originals, as well as copies Western Christian monks made of Byzantine works. The resulting conglomerate libraries are the basis of every modern library today.
Buddhist scriptures, educational materials, and histories were stored in libraries in pre-modern Southeast Asia. In Burma, a royal library called the Pitaka Taik was legendarily founded by King Anawrahta;[55] in the 18th century, British envoy Michael Symes, on visiting this library, wrote that "it is not improbable that his Birman majesty may possess a more numerous library than any potentate, from the banks of the Danube to the borders of China". In Thailand libraries called ho trai were built throughout the country, usually on stilts above a pond to prevent bugs from eating at the books.
In the Early Middle Ages, monastery libraries developed, such as the important one at the Abbey of Montecassino in Italy.[56] Books were usually chained to the shelves, reflecting the fact that manuscripts, which were created via the labour-intensive process of hand copying, were valuable possessions.[57] Despite this protectiveness, many libraries loaned books if provided with security deposits (usually money or a book of equal value). Lending was a means by which books could be copied and spread. In 1212 the council of Paris condemned those monasteries that still forbade loaning books, reminding them that lending is "one of the chief works of mercy."[58] The early libraries located in monastic cloisters and associated with scriptoria were collections of lecterns with books chained to them. Shelves built above and between back-to-back lecterns were the beginning of bookpresses. The chain was attached at the fore-edge of a book rather than to its spine. Book presses came to be arranged in carrels (perpendicular to the walls and therefore to the windows) in order to maximize lighting, with low bookcases in front of the windows. This "stall system" (i.e. fixed bookcases perpendicular to exterior walls pierced by closely spaced windows) was characteristic of English institutional libraries. In European libraries, bookcases were arranged parallel to and against the walls. This "wall system" was first introduced on a large scale in Spain's El Escorial.
Also, in Eastern Christianity monastery libraries kept important manuscripts. The most important of them were the ones in the monasteries of Mount Athos for Orthodox Christians, and the library of the Saint Catherine's Monastery in the Sinai Peninsula, Egypt for the Coptic Church.
From the 15th century in central and northern Italy, libraries of humanists and their enlightened patrons provided a nucleus around which an "academy" of scholars congregated in each Italian city of consequence. Malatesta Novello, lord of Cesena, founded the Malatestiana Library. Cosimo de Medici in Florence established his own collection, which formed the basis of the Laurentian Library.[59] In Rome, the papal collections were brought together by Pope Nicholas V, in separate Greek and Latin libraries, and housed by Pope Sixtus IV, who consigned the Bibliotheca Apostolica Vaticana to the care of his librarian, the humanist Bartolomeo Platina in February 1475.[60] In the 16th century Sixtus V bisected Bramante's Cortile del Belvedere with a cross-wing to house the Apostolic Library in suitable magnificence. The 16th and 17th centuries saw other privately endowed libraries assembled in Rome: the Vallicelliana, formed from the books of Saint Filippo Neri, with other distinguished libraries such as that of Cesare Baronio, the Biblioteca Angelica founded by the Augustinian Angelo Rocca, which was the only truly public library in Counter-Reformation Rome; the Biblioteca Alessandrina with which Pope Alexander VII endowed the University of Rome; the Biblioteca Casanatense of the Cardinal Girolamo Casanate; and finally the Biblioteca Corsiniana founded by the bibliophile Clement XII Corsini and his nephew Cardinal Neri Corsini, still housed in Palazzo Corsini in via della Lungara. The Republic of Venice patronized the foundation of the Biblioteca Marciana, based on the library of Cardinal Basilios Bessarion. In Milan Cardinal Federico Borromeo founded the Biblioteca Ambrosiana.
This trend soon spread outside of Italy, for example Louis III, Elector Palatine founded the Bibliotheca Palatina of Heidelberg.
These libraries don't have as many volumes as the modern libraries. However, they keep many valuable manuscripts of Greek, Latin and Biblical works.
Tianyi Chamber, founded in 1561 by Fan Qin during the Ming Dynasty, is the oldest existing library in China. In its heyday it boasted a collection of 70,000 volumes of antique books.
The 17th and 18th centuries include what is known as a golden age of libraries;[61] during this some of the more important libraries were founded in Europe, such as the Bodleian Library at Oxford, the British Museum Library in London, the Mazarine Library and the Bibliothèque Sainte-Geneviève in Paris, the Austrian National Library in Vienna, the National Central Library in Florence, the Prussian State Library in Berlin, the Załuski Library in Warsaw and the M.E. Saltykov-Shchedrin State Public Library of St Petersburg.[62]
The 18th century is considered to be an advancement to all cultural developments in library history, and it is at this time that we see the beginning of the functional library. In France, the French Revolution saw the confiscation in 1789 of church libraries and rich nobles' private libraries, and their collections became state property. The confiscated stock became part of a new national library – the Bibliothèque Nationale. Two famous librarians, Hubert-Pascal Ameilhon and Joseph Van Praet, selected and identified over 300,000 books and manuscripts that became the property of the people in the Bibliothèque Nationale.[63] During the French Revolution, librarians were solely responsible for the bibliographic planning of the nation. Out of this came the implementation of the concept of library service – the democratic extension of library services to the general public regardless of wealth or education.[63]
Many institutions make a distinction between a circulating or lending library, where materials are expected and intended to be loaned to patrons, institutions, or other libraries, and a reference library where material is not lent out. Modern libraries are often a mixture of both, containing a general collection for circulation, and a reference collection which is restricted to the library premises. Also, increasingly, digital collections enable broader access to material that may not circulate in print, and enables libraries to expand their collections even without building a larger facility.
An academic library is generally located on the campuses of colleges and universities and serve primarily the students and faculty of that and other academic institutions. Some academic libraries, especially those at public institutions, are accessible to members of the general public in whole or in part.
Academic libraries are libraries that are hosted in post-secondary educational institutions, such as colleges and universities. The main functions of an academic library are to provide resources and research support for students and faculty of the educational institution. Specific course-related resources are usually provided by the library, such as copies of textbooks and article readings held on 'reserve' (meaning that they are loaned out only on a short-term basis, usually a matter of hours).
Academic libraries offer workshops and courses outside of formal, graded coursework, which are meant to provide students with the tools necessary to succeed in their programs.[64] These workshops may include help with citations, effective search techniques, journal databases, and electronic citation software. These workshops provide students with skills that can help them achieve success in their academic careers (and often, in their future occupations), which they may not learn inside the classroom.
The academic library provides a quiet study space for students on campus; it may also provide group study space, such as meeting rooms. In North America, Europe, and other parts of the world, academic libraries are becoming increasingly digitally oriented. The library provides a "gateway" for students and researchers to access various resources, both print/physical and digital.[65] Academic institutions are subscribing to electronic journals databases, providing research and scholarly writing software, and usually provide computer workstations or computer labs for students to access journals, library search databases and portals, institutional electronic resources, internet access, and course- or task-related software (i.e. word processing and spreadsheet software). They are increasingly acting as an electronic repository for institutional scholarly research and academic knowledge, such as the collection and curation of digital copies of students' theses and dissertations.[66][67]
Children's libraries are special collections of books intended for juvenile readers and usually kept in separate rooms of general public libraries. Some children's libraries have entire floors or wings dedicated to them in bigger libraries while smaller ones may have a separate room or area for children. They are an educational agency seeking to acquaint the young with the world's literature and to cultivate a love for reading. Their work supplements that of the public schools.[68]
Services commonly provided by public libraries may include storytelling sessions for infants, toddlers, preschool children, or after-school programs, all with an intention of developing early literacy skills and a love of books. One of the most popular programs offered in public libraries are summer reading programs for children, families, and adults.[69]
Another popular reading program for children is PAWS TO READ or similar programs where children can read to certified therapy dogs. Since animals are a calming influence and there is no judgment children learn confidence and a love of reading. Many states have these types of programs parents just have to ask their librarian to see if it is available at their local library.[70]
A national or state library serves as a national repository of information, and has the right of legal deposit, which is a legal requirement that publishers in the country need to deposit a copy of each publication with the library. Unlike a public library, a national library rarely allows citizens to borrow books. Often, their collections include numerous rare, valuable, or significant works. There are wider definitions of a national library, putting less emphasis on the repository character.[71][72] The first national libraries had their origins in the royal collections of the sovereign or some other supreme body of the state.
Many national libraries cooperate within the National Libraries Section of the International Federation of Library Associations and Institutions (IFLA) to discuss their common tasks, define and promote common standards and carry out projects helping them to fulfil their duties. The national libraries of Europe participate in The European Library which is a service of the Conference of European National Librarians (CENL).
A public library provides services to the general public and usually makes at least some of its books available for borrowing. Typically, libraries issue library cards to community members wishing to borrow books. Many public libraries also serve as community organizations that provide free services and events to the public, such as reading groups and toddler story time.
The earliest example in England of a library to be endowed for the benefit of users who were not members of an institution such as a cathedral or college was the Francis Trigge Chained Library in Grantham, Lincolnshire, established in 1598. The library still exists and can justifiably claim to be the forerunner of later public library systems. The beginning of the modern, free, open access libraries really got its start in the U.K. in 1847. Parliament appointed a committee, led by William Ewart, on Public Libraries to consider the necessity of establishing libraries through the nation: In 1849 their report noted the poor condition of library service, it recommended the establishment of free public libraries all over the country, and it led to the Public Libraries Act in 1850, which allowed all cities with populations exceeding 10,000 to levy taxes for the support of public libraries. Another important act was the 1870 Public School Law, which increased literacy, thereby the demand for libraries, so by 1877, more than 75 cities had established free libraries, and by 1900 the number had reached 300.[73] This finally marks the start of the public library as we know it. And these acts influenced similar laws in other countries, most notably the U.S. The first tax-supported public library in the United States was Peterborough, New Hampshire (1833) first supported by state funds then an "Act Providing for the Establishment of Public Libraries" in 1849.[74]
The year 1876 is key in the history of librarianship in the United States. The American Library Association was formed, as well as The American Library Journal, Melvil Dewey published his decimal-based system of classification, and the United States Bureau of Education published its report, "Public libraries in the United States of America; their history, condition, and management." During the post-Civil War years, there was a rise in the establishment of public libraries, a movement led chiefly by newly formed women's clubs. They contributed their own collections of books, conducted lengthy fund raising campaigns for buildings, and lobbied within their communities for financial support for libraries, as well as with legislatures and the Carnegie Library Endowment founded in the 20th century.[75] They led the establishment of 75–80 percent of the libraries in communities across the country.[76]
In 1979 and 1991 White House Conferences on Library and Information Services (WHCLIS) were held to demonstrate the key role libraries play in American democracy.[77]
The American Library Association (ALA) continues to play a major role in libraries to this day, with its public library focused division, the Public Library Association, establishing standards and planning guidelines.[78] Dewey's classification system, although under heavy criticism of late,[citation needed] still remains the prevailing method of classification used in the United States.
As the number of books in libraries increased, so did the need for compact storage and access with adequate lighting, giving birth to the stack system, which involved keeping a library's collection of books in a space separate from the reading room. This arrangement arose in the 19th century. Book stacks quickly evolved into a fairly standard form in which the cast iron and steel frameworks supporting the bookshelves also supported the floors, which often were built of translucent blocks to permit the passage of light (but were not transparent, for reasons of modesty). The introduction of electrical lighting had a huge impact on how the library operated. The use of glass floors was largely discontinued, though floors were still often composed of metal grating to allow air to circulate in multi-story stacks. As more space was needed, a method of moving shelves on tracks (compact shelving) was introduced to cut down on otherwise wasted aisle space.
In China, there were 2,925 public libraries in 2011.[79]
Library 2.0, a term coined in 2005, is the library's response to the challenge of Google and an attempt to meet the changing needs of users by using web 2.0 technology. Some of the aspects of Library 2.0 include, commenting, tagging, bookmarking, discussions, use of online social networks by libraries, plug-ins, and widgets.[80] Inspired by web 2.0, it is an attempt to make the library a more user-driven institution.
Despite the importance of public libraries, they are routinely having their budgets cut by state legislature. Funding has dwindled so badly that some smaller public libraries have been forced to cut their hours and release employees.
A reference library does not lend books and other items; instead, they must be read at the library itself. Typically such libraries are used for research purposes, for example at a university. Some items at reference libraries may be historical and even unique. Examples of reference libraries include the British Library in London and the Bodleian Library at Oxford University. Many lending libraries contain a "reference section", which holds books, such as dictionaries, which are common reference books, and are therefore not lent out.[81] Such reference sections may be referred to as "reading rooms", which may also include newspapers and periodicals.[82]
A research library is a collection of materials on one or more subjects.[83] A research library supports scholarly or scientific research and will generally include primary as well as secondary sources; it will maintain permanent collections and attempt to provide access to all necessary materials. A research library is most often an academic or national library, but a large special library may have a research library within its special field and a very few of the largest public libraries also serve as research libraries. A large university library may be considered a research library; and in North America such libraries may belong to the Association of Research Libraries.[84] In the United Kingdom they may be members of Research Libraries UK (RLUK).[85]
A research library can be either a reference library, which does not lend its holdings, or a lending library, which does lend all or some of its holdings. Some extremely large or traditional research libraries are entirely reference in this sense, lending none of their materials; most academic research libraries, at least in the U.S. and the U.K., now lend books, but not periodicals or other materials. Many research libraries are attached to a parental organization and serve only members of that organization.
All other libraries fall into the "special library" category. Many private businesses and public organizations, including hospitals, museums, research laboratories, law firms, and many government departments and agencies, maintain their own libraries for the use of their employees in doing specialized research related to their work. Depending on the particular institution, special libraries may or may not be accessible to the general public or elements thereof. In more specialized institutions such as law firms and research laboratories, librarians employed in special libraries are commonly specialists in the institution's field rather than generally trained librarians, and often are not required to have advanced degrees in specifically library-related field due to the specialized content and clientele of the library.
Some special libraries, such as governmental law libraries, hospital libraries, and military base libraries commonly are open to public visitors to the institution in question. Depending on the particular library and the clientele it serves, special libraries may offer services similar to research, reference, public, academic, or children's libraries, often with restrictions such as only lending books to patients at a hospital or restricting the public from parts of a military collection. Given the highly individual nature of special libraries, visitors to a special library are often advised to check what services and restrictions apply at that particular library.
Special libraries are distinguished from special collections, which are branches or parts of a library intended for rare books, manuscripts, and other special materials, though some special libraries have special collections of their own, typically related to the library's specialized subject area.
For more information on specific types of special libraries, see law libraries, medical libraries, music libraries, or transportation libraries.
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Most libraries have materials arranged in a specified order according to a library classification system, so that items may be located quickly and collections may be browsed efficiently. Some libraries have additional galleries beyond the public ones, where reference materials are stored. These reference stacks may be open to selected members of the public. Others require patrons to submit a "stack request," which is a request for an assistant to retrieve the material from the closed stacks: see List of closed stack libraries (in progress).
Larger libraries are often divided into departments staffed by both paraprofessionals and professional librarians.
Basic tasks in library management include the planning of acquisitions (which materials the library should acquire, by purchase or otherwise), library classification of acquired materials, preservation of materials (especially rare and fragile archival materials such as manuscripts), the deaccessioning of materials, patron borrowing of materials, and developing and administering library computer systems. More long-term issues include the planning of the construction of new libraries or extensions to existing ones, and the development and implementation of outreach services and reading-enhancement services (such as adult literacy and children's programming).
The International Organization for Standardization (ISO) has published several standards regarding the management of libraries through its Technical Committee 46 (TC 46),[87] which is focused on "libraries, documentation and information centers, publishing, archives, records management, museum documentation, indexing and abstracting services, and information science". The following is a partial list of some of them:[88]
Librarians have sometimes complained that some of the library buildings which have been used to accommodate libraries have been inadequate for the demands made upon them. In general this condition may have resulted from one or more of the following causes:
Much advancement has undoubtedly been made toward cooperation between architect and librarian,[when?] and many good designers have made library buildings their specialty, nevertheless it seems that the ideal type of library is not yet realized—the type so adapted to its purpose that it would be immediately recognized as such, as is the case with school buildings at the present time.[when?] This does not mean that library constructions should conform rigidly to a fixed standard of appearance and arrangement, but it does mean that the exterior should express as nearly as possible the purpose and functions of the interior.[89]
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Patrons may not know how to fully use the library's resources. This can be due to some individuals' unease in approaching a staff member. Ways in which a library's content is displayed or accessed may have the most impact on use. An antiquated or clumsy search system, or staff unwilling or untrained to engage their patrons, will limit a library's usefulness. In the public libraries of the United States, beginning in the 19th century, these problems drove the emergence of the library instruction movement, which advocated library user education. One of the early leaders was John Cotton Dana. The basic form of library instruction is sometimes known as information literacy.
Libraries should inform their users of what materials are available in their collections and how to access that information. Before the computer age, this was accomplished by the card catalogue—a cabinet (or multiple cabinets) containing many drawers filled with index cards that identified books and other materials. In a large library, the card catalogue often filled a large room. The emergence of the Internet, however, has led to the adoption of electronic catalogue databases (often referred to as "webcats" or as online public access catalogues, OPACs), which allow users to search the library's holdings from any location with Internet access. This style of catalogue maintenance is compatible with new types of libraries, such as digital libraries and distributed libraries, as well as older libraries that have been retrofitted. Electronic catalogue databases are criticized by some who believe that the old card catalogue system was both easier to navigate and allowed retention of information, by writing directly on the cards, that is lost in the electronic systems.[90] This argument is analogous to the debate over paper books and e-books. While libraries have been accused of precipitously throwing out valuable information in card catalogues, most modern ones have nonetheless made the move to electronic catalogue databases. Large libraries may be scattered within multiple buildings across a town, each having multiple floors, with multiple rooms housing the resources across a series of shelves. Once a user has located a resource within the catalogue, they must then use navigational guidance to retrieve the resource physically; a process that may be assisted through signage, maps, GPS systems or RFID tagging.
Finland has the highest number of registered book borrowers per capita in the world. Over half of Finland's population are registered borrowers.[91] In the U.S., public library users have borrowed on average roughly 15 books per user per year from 1856 to 1978. From 1978 to 2004, book circulation per user declined approximately 50%. The growth of audiovisuals circulation, estimated at 25% of total circulation in 2004, accounts for about half of this decline.[92]
In the 21st century there has been increasing use of the Internet to gather and retrieve data. The shift to digital libraries has greatly impacted the way people use physical libraries. Between 2002 and 2004, the average American academic library saw the overall number of transactions decline approximately 2.2%.[93] Libraries are trying to keep up with the digital world and the new generation of students that are used to having information just one click away. For example, the University of California Library System saw a 54% decline in circulation between 1991 to 2001 of 8,377,000 books to 3,832,000.[94]
These facts might be a consequence of the increased availability of e-resources. In 1999–2000, 105 ARL university libraries spent almost $100 million on electronic resources, which is an increase of nearly $23 million from the previous year.[95] A 2003 report by the Open E-book Forum found that close to a million e-books had been sold in 2002, generating nearly $8 million in revenue.[96] Another example of the shift to digital libraries can be seen in Cushing Academy’s decision to dispense with its library of printed books—more than 20,000 volumes in all—and switch over entirely to digital media resources.[97]
One claim to why there is a decrease in the usage of libraries stems from the observation of the research habits of undergraduate students enrolled in colleges and universities. There have been claims that college undergraduates have become more used to retrieving information from the Internet than a traditional library. As each generation becomes more in tune with the Internet, their desire to retrieve information as quickly and easily as possible has increased. Finding information by simply searching the Internet could be much easier and faster than reading an entire book. In a survey conducted by NetLibrary, 93% of undergraduate students claimed that finding information online makes more sense to them than going to the library. Also, 75% of students surveyed claimed that they did not have enough time to go to the library and that they liked the convenience of the Internet. While the retrieving information from the Internet may be efficient and time saving than visiting a traditional library, research has shown that undergraduates are most likely searching only .03% of the entire web.[98] The information that they are finding might be easy to retrieve and more readily available, but may not be as in depth as information from other resources such as the books available at a physical library.
In the mid-2000s Swedish company Distec invented a library book vending machine known as the GoLibrary, that offers library books to people where there is no branch, limited hours, or high traffic locations such as El Cerrito del Norte BART station in California.
A library may make use of the Internet in a number of ways. A library may make the contents of its catalogues searchable online. Some specialised search engines such as Google Scholar offer a way to facilitate searching for academic resources such as journal articles and research papers. The Online Computer Library Center allows library records to be searched online through its WorldCat database.[99] Websites such as LibraryThing and Amazon provide abstracts, reviews and recommendations of books.[99] Libraries provide computers and Internet access to allow people to search for information online.[100] Online information access is particularly attractive to younger library users.[101][102][103][104]
Digitization of books, particularly those that are out-of-print, in projects such as Google Books provides resources for library and other online users. Due to their holdings of valuable material, some libraries are important partners for search engines such as Google in realizing the potential of such projects and have received reciprocal benefits in cases where they have negotiated effectively.[105] As the prominence of and reliance on the Internet has grown, library services have moved the emphasis from mainly providing print resources to providing more computers and more Internet access.[106] Libraries face a number of challenges in adapting to new ways of information seeking that may stress convenience over quality,[107] reducing the priority of information literacy skills.[108] The potential decline in library usage, particularly reference services,[109] puts the necessity for these services in doubt.
Library scholars have acknowledged that libraries need to address the ways that they market their services if they are to compete with the Internet and mitigate the risk of losing users.[110] This includes promoting the information literacy skills training considered vital across the library profession.[108][111][112] However, marketing of services has to be adequately supported financially in order to be successful. This can be problematic for library services that are publicly funded and find it difficult to justify diverting tight funds to apparently peripheral areas such as branding and marketing.[113]
The International Federation of Library Associations and Institutions (IFLA) is the leading international association of library organisations. It is the global voice of the library and information profession, and its annual conference provides a venue for librarians to learn from one another.[114]
National associations of the English-speaking world include the American Library Association, the Australian Library and Information Association, the Canadian Library Association and the Research Libraries UK (a consortium of 30 university and other research libraries in the United Kingdom). Library bodies such as CILIP (formerly the Library Association, founded 1877) may advocate the role that libraries and librarians can play in a modern Internet environment, and in the teaching of information literacy skills.[111][115]
Library associations in Asia include the Indian Library Association (ILA),[116] Indian Association of Special Libraries and Information Centers (IASLIC),[117] Bengal Library Association (BLA), Kolkata,[118] Pakistan Library Association,[119] the Pakistan Librarians Welfare Organization,[120] the Bangladesh Association of Librarians, Information Scientists and Documentalists, the Library Association of Bangladesh and the Sri Lanka Library Association (founded 1960).
Public library advocacy is support given to a public library for its financial and philosophical goals or needs. Most often this takes the form of monetary or material donations or campaigning to the institutions which oversee the library, sometimes by advocacy groups such as Friends of Libraries. Originally, library advocacy was centred on the library itself, but current trends show libraries positioning themselves to demonstrate they provide "economic value to the community."[121]
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In the United States, state library agencies have oversight of the public library situation within their boundaries. State library legislation has concerned itself mainly with the following topics:
Legislative reference bureaus and provision for popular lectures and for educational extension by means of the library are provided for by some states.[122]
The centrality of the Qurʾān as the prototype of the written word in Islam bears significantly on the role of books within its intellectual tradition and educational system.[123] An early impulse in Islam was to manage reports of events, key figures and their sayings and actions. Thus, "the onus of being the last 'People of the Book' engendered an ethos of [librarianship]"[124] early on and the establishment of important book repositories throughout the Muslim world has occurred ever since.
Upon the spread of Islam, libraries in newly Islamic lands knew a brief period of expansion in the Middle East, North Africa, Sicily and Spain. Like the Christian libraries, they mostly contained books which were made of paper, and took a codex or modern form instead of scrolls; they could be found in mosques, private homes, and universities, from Timbuktu to Afghanistan and modern day Pakistan. In Aleppo, for example, the largest and probably the oldest mosque library, the Sufiya, located at the city's Grand Umayyad Mosque, contained a large book collection of which 10,000 volumes were reportedly bequeathed by the city's most famous ruler, Prince Sayf al-Dawla.[125] Ibn al-Nadim's bibliography Fihrist demonstrates the devotion of medieval Muslim scholars to books and reliable sources; it contains a description of thousands of books circulating in the Islamic world circa 1000, including an entire section for books about the doctrines of other religions. Modern Islamic libraries for the most part do not hold these antique books; many were lost, destroyed by Mongols,[126] or removed to European libraries and museums during the colonial period.[127]
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| リンク元 | 「ライブラリー」「図書館」「ライブラリ」 |
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