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= LaTeX =
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Introduction
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LaTeX ( or , 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).
History
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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 sold hundreds of thousands of
copies. Meanwhile, Lamport released versions of his LaTeX macros in
1984 and 1985. On 21 August 1989, at a TeX Users Group (TUG) meeting
at Stanford, Lamport agreed to turn over maintenance and development
of LaTeX to Frank Mittelbach. Frank Mittelbach, along with Chris
Rowley and Rainer Schöpf, formed the LaTeX3 team; in 1994, they
released LaTeX2e, the current standard version. LaTeX3 has since been
cancelled with features intended for that version being back-ported to
LaTeX2e since 2018.
Typesetting system
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LaTeX attempts to follow the design philosophy of separating
presentation from content, so that authors can focus on the content of
what they are writing without attending simultaneously to its visual
appearance. In preparing a LaTeX document, the author specifies the
logical structure using simple, familiar concepts such as 'chapter',
'section', 'table', 'figure', etc., and lets the LaTeX system handle
the formatting and layout of these structures. As a result, it
encourages the separation of the layout from the content — while still
allowing manual typesetting adjustments whenever needed. This concept
is similar to the mechanism by which many word processors allow styles
to be defined globally for an entire document, or the use of Cascading
Style Sheets in styling HyperText Markup Language (HTML) documents.
The LaTeX system is a markup language that handles typesetting and
rendering, 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.
Example
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The example below shows the input to LaTeX and the corresponding
output from the system:
Input Output
\documentclass{article} % Starts an article \usepackage{amsmath} %
Imports amsmath \title{\LaTeX} % Title \begin{document} % Begins a
document \maketitle \LaTeX{} is a document preparation system for
the \TeX{} typesetting program. It offers programmable desktop
publishing features and extensive facilities for automating most
aspects of typesetting and desktop publishing, including numbering
and cross-referencing, tables and figures, page layout,
bibliographies, and much more. \LaTeX{} was originally written in
1984 by Leslie Lamport and has become the dominant method for using
\TeX; few people write in plain \TeX{} anymore. The current version
is \LaTeXe. % This is a comment, not shown in final output. % The
following shows typesetting power of LaTeX: \begin{align} E_0
&= mc^2 \\ E &= \frac{mc^2}{\sqrt{1-\frac{v^2}{c^2}}}
\end{align} \end{document} 500px
Pronouncing and writing "LaTeX"
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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 ('skill', 'art', 'technique'); for this reason, TeX's creator
Donald Knuth promotes its pronunciation as () (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.
Related software
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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.
Compatibility and converters
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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.
Licensing
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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.
Versions
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LaTeX2e is the current version of LaTeX, since it replaced LaTeX 2.09
in 1994. , LaTeX3, which started in the early 1990s, is under a
long-term development project. Planned features include improved
syntax (separation of content from styling), hyperlink support, a new
user interface, access to arbitrary fonts and a new documentation.
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.
There are many commercial implementations of the entire TeX system.
System vendors may add extra features like added typefaces and
telephone support. LyX is a free software, WYSIWYM visual document
processor that uses LaTeX for a back-end. 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.
See also
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* BibTeX - reference management software usually used with LaTeX
* Formula editor
* Help:Displaying a formula
* KaTeX
* List of document markup languages
* List of TeX extensions
* Lout (software)
* MathJax
* xdvi - software to view DVI files while using Unix
License
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All content on Gopherpedia comes from Wikipedia, and is licensed under CC-BY-SA
License URL:
http://creativecommons.org/licenses/by-sa/3.0/
Original Article:
http://en.wikipedia.org/wiki/LaTeX
