There are two versions of LaTeX in widespread use: LaTeX2e and LaTeX 2.09. LaTeX2e is the current version of LaTeX since it replaced LaTeX 2.09 in 1994. LaTeX 2.09 is now obsolete and is no longer supported but is still used by many people who see no reason to switch to LaTeX2e. If you are a newcomer you definitely want to learn and use only LaTeX2e. How do you know which version is which? LaTeX 2.09 files begin with the command “\documentstyle”, while LaTeX2e files begin with “\documentclass”. Fortunately, when you run the command “latex” on your file, the software automatically figures out which version you're using and does the right things.

• LaTeX documents (.tex) can be opened with any text editor. They consist of plain text and do not contain hidden formatting codes.


• TeX documents can be shared by rendering the LaTeX file to Rich Text Format (.rtf) or Extensible Markup Language (.xml). 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. It is licensed under the Q Public License.


• LaTeX.html is a converter written in Perl that converts LaTeX documents to.html. This way, e.g., scientific papers, primarily typeset for printing, can be placed on the Web. It is licensed under GNU GPL v2. The latest updates are available from CTAN.


• LaTeXML is a free, public domain software which converts LaTeX documents to a variety of structured formats including.html5, epub, jats, tei.


• Pandoc is an “universal document converter” able to transform LaTeX into many different file formats including.html5, epub, rtf and docx. It is licensed under GNU GPL v2.

LaTeX follows 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 worry about the formatting and layout of these structures. It still allows manual typesetting adjustments where needed. This concept is similar to the use of Cascading Style Sheets to style.html. This approach is defined WYSIWYM (What You See Is What You Mean) and it is the difference of working with LaTeX or with WYSIWYG (What You See Is What You Get) word-processing as Microsoft Word.

The LaTeX system is a markup language that also handles typesetting and rendering. LaTeX can be arbitrarily extended by using the underlying macro language to develop custom formats. Such macros are often collected into packages, which are available to address special formatting issues such as complicated mathematical content or graphics.