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Formatting Information — An introduction to typesetting with LATEX

Chapter 3: Packages and CTAN

In this chapter…

  1. Packages and classes
  2. Installing classes and packages
  3. Online help

The Comprehensive TEX Archive Network (CTAN) is a repository of Web documents and files from HTTP and FTP servers worldwide which contain copies of almost every piece of free software related to TEX and LATEX.

CTAN is based on three main servers, and there are several online indexes available. There are complete TEX and LATEX systems for all platforms, utilities for text and graphics processing, conversion programs into and out of LATEX, printer drivers, extra typefaces, and (possibly the most important) the LATEX packages. The three main servers are:

In addition, there are dozens of mirrors of CTAN around the world, run by ISPs, companies, universities, and other institutions. These automatically update themselves from the three main servers, so for a speedy download from your closest server, you can go to and it will redirect you to your nearest mirror site.

  1. For example, there is no xcolor.dtx and xcolor.ins for the xcolor package because it forms part of the graphics bundle, which is included with all LATEX systems anyway. Such packages change very rarely, as they form part of the core of LATEX and are very stable. You should never try to update these packages in isolation. 

  2. Almost all of these have been updated to work with LATEX, so they should be installed as in the penultimate step ‘Install the files’, but there are a few remaining. 

  3. MiK TEX users should note that you cannot process .ins files inside MiK TEX’s own folders: you have to do this elsewhere first, hence the need for a temporary directory. 

  4. Note that this means newsreaders for the Usenet News (NNTP) service. It does not mean syndication readers for RSS, which are a different thing entirely — these are unfortunately also sometimes referred to as ‘newsreaders’.