Система подготовки документов LaTeX

Document preparation software system

LaTeX ('/l//ɑː//t//ɛ//k/ LAHtek or '/l//e://t//ɛ//k/ LAYtek, often stylized as ) is a software system for typesetting documents. LaTeX markup describes the content and layout of the document, as opposed to the formatted text found in WYSIWYG word processors like Microsoft Word, LibreOffice Writer and Apple Pages. The writer uses markup tagging conventions to define the general structure of a document, to stylise text throughout a document (such as bold and italics), and to add citations and cross references. A TeX distribution such as TeX Live or MiKTeX is used to produce an output file (such as PDF or DVI) suitable for printing or digital distribution. LaTeX is widely used in academia for the communication and publication of scientific documents and technical note taking in many fields. It also has a prominent role in the preparation and publication of books and articles that contain complex multilingual materials, such as Arabic and Greek. LaTeX uses the TeX typesetting program for formatting its output, and is itself written in the TeX macro language. LaTeX can be used as a standalone document preparation system, or as an intermediate format. In the latter role, for example, it is sometimes used as part of a pipeline for translating DocBook and other XML based formats for PDF. The typesetting system offers programmable desktop publishing features and extensive facilities for automating most aspects of typesetting and desktop publishing, including numbering and cross referencing of tables and figures, chapter and section headings, graphics, page layout, indexing and bibliographies. Like TeX, LaTeX started as a writing tool for mathematicians and computer scientists, but even from early in its development, it has also been taken up by scholars who needed to write documents that include complex math expressions or non Latin scripts, such as Arabic, Devanagari and Chinese. LaTeX is intended to provide a high level, descriptive markup language that accesses the power of TeX in an easier way for writers. In essence, TeX handles the layout side, while LaTeX handles the content side for document processing. LaTeX comprises a collection of TeX macros and a program to process LaTeX documents, and because the plain TeX formatting commands are elementary, it provides authors with ready made commands for formatting and layout requirements such as chapter headings, footnotes, cross references and bibliographies. LaTeX was originally written in the early 1980s by Leslie Lamport at SRI International. The current version is LaTeX2e (stylised as ), first released in 1994 but incrementally updated starting in 2015. This update policy replaced earlier plans for a separate release of LaTeX3 , which had been in development since 1989. LaTeX is free software and is distributed under the LaTeX Project Public License (LPPL).

LaTeX was created in the early 1980s by Leslie Lamport when he was working at Stanford Research Institute (SRI). He needed to write TeX macros for his own use and thought that with a little extra effort, he could make a general package usable by others. Peter Gordon, an editor at Addison Wesley, convinced him to write a LaTeX user's manual for publication (Lamport was initially skeptical that anyone would pay money for it); it came out in 1986 and can be arbitrarily extended by using the underlying macro language to develop custom macros such as new environments and commands. Such macros are often collected into packages, which could then be made available to address some specific typesetting needs such as the formatting of complex mathematical expressions or graphics (e. g., the use of the align environment provided by the amsmath package to produce aligned equations). To create a document in LaTeX, a user first creates a file, such as document. tex, typically using a text editor. The user then gives their document. tex file as input to the TeX program (with the LaTeX macros loaded), which prompts TeX to write out a file suitable for onscreen viewing or printing. This write format preview cycle is one of the chief ways in which working with LaTeX differs from the What You See Is What You Get (WYSIWYG) style of document editing. It is similar to the code compile execute cycle known to computer programmers. Today, many LaTeX aware editing programs make this cycle a simple matter through the pressing of a single key, while showing the output preview on the screen beside the input window. Some online LaTeX editors even automatically refresh the preview, while other online tools provide incremental editing in place, mixed in with the preview in a streamlined single window.

The characters 'T', 'E', and 'X' in the name come from the Greek capital letters tau, epsilon, and chi, as the name of TeX derives from the τέχνη ('skill', 'art', 'technique'); for this reason, TeX's creator Donald Knuth promotes its pronunciation as /t//ɛ//x/ (tekh) (that is, with a voiceless velar fricative as in Modern Greek, similar to the ch in loch). Lamport remarks that "TeX is usually pronounced tech, making lah tech, lah tech, and lay tech the logical choices; but language is not always logical, so lay tecks is also possible." The name is printed in running text with a typographical logo: In media where the logo cannot be precisely reproduced in running text, the word is typically given the unique capitalization LaTeX. Alternatively, the TeX, LaTeX and XeTeX logos can also be rendered via pure CSS and XHTML for use in graphical web browsers — by following the specifications of the internal \LaTeX macro.

As a macro package, LaTeX provides a set of macros for TeX to interpret. There are many other macro packages for TeX, including Plain TeX, GNU Texinfo, AMSTeX, and ConTeXt. When TeX "compiles" a document, it follows (from the user's point of view) the following processing sequence: Macros → TeX → Driver → Output. Different implementations of each of these steps are typically available in TeX distributions. Traditional TeX will output a DVI file, which is usually converted to a PostScript file. 2000, Hàn Thế Thành and others have written a new implementation of TeX called pdfTeX, which also outputs to PDF and takes advantage of features available in that format. The XeTeX engine developed by Jonathan Kew, on the other hand, merges modern font technologies and Unicode with TeX. LuaTeX is an extended version of pdfTeX using Lua as an embedded scripting language. There are also many editors for LaTeX, some of which are offline, source code based while others are online, partial WYSIWYG based. For more, see Comparison of TeX editors.

LaTeX documents (*. tex) can be opened with any text editor. They consist of plain text and contain no hidden formatting codes or binary instructions. Also, TeX documents can be shared by rendering the LaTeX file to Rich Text Format (RTF), XML, or class files. This can be done using the free software programs LaTeX2RTF or TeX4ht. LaTeX can also be rendered to PDF files using the LaTeX extension pdfLaTeX. LaTeX files containing Unicode text can be processed into PDFs with the inputenc package, or by the TeX extensions XeLaTeX and LuaLaTeX. HeVeA is a converter written in OCaml that converts LaTeX documents to HTML5. This way documents such as scientific papers, primarily typeset for printing, can be placed on the World Wide Web for online viewing. It is licensed under the Q Public License. LaTeX2HTML is a converter written in Perl that converts LaTeX documents to HTML. It is licensed under the GNU General Public License (GPL) v2. The latest updates are available from Comprehensive TeX Archive Network (CTAN). LaTeXML is a converter written in Perl that converts LaTeX documents into a variety of XML based formats, including HTML5 (with MathML), ePub ebooks, JATS, and TEI. It was developed at the National Institute of Standards and Technology by US Federal Government employees and is therefore in the public domain. It is available for free. Pandoc is a "universal document converter" able to transform LaTeX (as well as other formats) into many different file formats, including HTML5, ePub, RTF, Microsoft Word (*. docx), and even text with MediaWiki markup as used in Wikipedia. It is licensed under GPL v2. LaTeX has become the de facto standard to typeset mathematical expression in scientific documents. Hence, there are several conversion tools focusing on mathematical LaTeX expressions, such as converters to MathML or Computer Algebra System. MathJax is a JavaScript library for converting LaTeX to MathML, picture formats including SVG and PNG, or HTML for embedding within a webpage. The Wikimedia Foundation uses MathJax to build Mathoid, a web service that uses Node. js to render math that is used in Wikipedia. KaTeX is a JavaScript library for converting LaTeX to HTML and MathML. It is developed by Khan Academy, and is among the fastest LaTeX to HTML converters.

LaTeX is typically distributed along with plain TeX under a free software license: the LaTeX Project Public License (LPPL). The LPPL is not compatible with the GNU General Public License, as it requires that modified files must be clearly differentiable from their originals (usually by changing the filename); this was done to ensure that files that depend on other files will produce the expected behavior and avoid dependency hell. The LPPL is Debian Free Software Guidelines (DFSG) compliant as of version 1.3. As free software, LaTeX is available on most operating systems, which include Unix (Solaris, HP UX, AIX), BSD (FreeBSD, macOS, NetBSD, OpenBSD), Linux (Red Hat, Debian, Arch, Gentoo), Windows, DOS, RISC OS, AmigaOS, and Plan 9.

LaTeX2e is the current version of LaTeX, since it replaced LaTeX 2.09 in 1994. as of 2020, LaTeX3, which started in the early 1990s, is under a long term development project. Some LaTeX3 features are available in LaTeX2e using packages, and by 2020 many features have been enabled in LaTeX2e by default for a gradual transition. TeXmacs is a free, WYSIWYG editor with similar functionalities as LaTeX, but with a different typesetting engine. Other WYSIWYG editors that produce LaTeX include Scientific Word on Windows, and BaKoMa TeX on Windows, Mac and Linux. Many community supported TeX distributions are available.