##  Class files

The styles, contents and layout in a LaTeX document are defined by means of tags or commands in a plain .tex file, this file can be used to generate several types of "human-readable" versions of the document. The easiest way to generate this final output is to use ShareLaTeX, ShareLaTeX has a ready-to-use LaTeX distribution and final documents can be generated by simply clicking the "Recompile" button; if this is your case you can skip this article. Otherwise, if you need to learn how to compile documents in your computer, this article describes how to generate PS, DVI and PDF output from a LaTeX file. Contents 1 Introduction 2 TeX distributions 3 LaTeX editors 4 Output formats 5 Compiling documents with cross-references 6 Reference guide 7 Further reading  Introduction LaTeX documents are plain documents with a .tex extension (see the Creating a document in LaTeX article for examples), this plain text file has some markup commands that are meant to format the document but, how do you actually generate the final output?. It depends on the type of document you want to generate. Suppose you saved your document and named the file "mydocument.tex". To create a .PDF file just run this command in the system terminal. pdflatex mydocument.tex And a file named "mydocument.pdf" will appear.  TeX distributions The set of programs that make possible to compile TeX and LaTeX documents is called a TeX typesetting or a TeX distribution. There are many TeX distributions available for different operating systems: MiKTeX for Windows TeX Live for Linux and other UNIX-like systems MacTeX redistribution of TeX Live for Mac OS X teTeX for Linux and other UNIX-like systems, now is no longer actively maintained proTeXt is based on MiKTeX Of course, if you don't want to go through the process of installing a TeX distribution, you can use an on-line ready to use option like ShareLaTeX.  LaTeX editors There are many advanced text editors specifically dedicated to LaTeX for the most popular operating systems, some of them can be downloaded for free while others are proprietary software: Open source: AUCTEX, GNU TeXmacs, Gummi, Kile, LaTeXila, MeWa, TeXShop, TeXnicCenter, Texmaker, TeXstudio, TeXworks Freeware: LEd, WinShell Proprietary/Shareware: Inlage, Scientific WorkPlace, WinEdt There are also general-purpose editors that add LaTeX-friendly options by means of plugins. For example the well known editors emacs and vim have both a LaTeX extension. It's worth to mention that the editor in ShareLaTeX can be customized to emulate the emacs or vim behaviour. It is also themeable, so you can choose the same syntax highlighting of some of the aforementioned editors.  Output formats There are three output formats available in all TeX distributions. To generate a specific output the document has to be compiled by running a command in a terminal (linux and osx) or the command prompt (windows). For example, if you want to compile a file named "mydocument.tex" you can use one of the next commands: latex mydocument.tex This will create "mydocument.dvi", a DVI document pdflatex mydocument.tex This will generate "mydocument.pdf", a PDF document There are some additional commands that allow conversion between formats, PS images are also supported. See the reference guide for a schematic description of commands and output formats. A description of each output format is provided below: (DVI) Device independent file format consists of binary data describing the visual layout of a document in a manner not reliant on any specific image format, display hardware or printer. (PS) PostScript file format describes text and graphics on page and it is based on vector graphics. PostScript is, until now, a standard in desktop publishing areas. (PDF) Portable Document Format is a file format, based on PostScript, used to represent documents in a manner independent of application software, hardware, and operating systems. It is now widely used as a file format for printing and for distribution on the Web. Note: Most of the editors nowadays include quick-access icons to compile to different output formats so you don't have to actually run the commands in a system prompt.  Compiling documents with cross-references In some cases, when your document includes cross-references, you must compile the source twice. It is necessary to include the correct numbers in the table of contents, list of images, reference numbers to theorems and so on. During the first compilation the LaTeX compiler writes the .aux file for informations about different numbering and during the second one the compiler reads these informations in order to properly generate a table of contents, bibliography, etc. This process can be automatized by the command latexmk. For example, to create a pdf out of the "mydocument.tex" file, run latexmk -pdf mydocument.tex only once, even if the document has referenced images and bibliography. You can change -pdf to -dvi to set a different file type.  Reference guide LaTeX compilation file flow  Further reading Creating a document in LaTeX Creating a document in ShareLaTeX Debugging Compilation timeout errors Multi-file LaTeX projects The not so short introduction to LaTeX2ε