What is CTAN?
The Comprehensive TeX Archive Network is a set of Internet sites around the world that offer TeX-related material for download.
CTAN is not a single site, but instead is a set of sites.
One of the sites is the core. This site actively manages the material, for instance, by accepting uploads of new or updated packages.
In addition, other sites around the world help out by mirroring. These sites automatically sync their TeX collections with a core site, and then in turn make their copies publicly available. This gives users close to their location better access, and relieves the core sites of network load. We maintain a list of official mirrors; please use one if you can.
Being a Mirror
If you are interested in being an official mirror, that'd be great. (Mirror traffic is light, perhaps one visitor is logged in at any time.) You will need about 50 Gb of hard disk space and an always-on Internet connection. For the setup details, see our mirroring page. Once you are ready, use the signup form on this page.
Before CTAN there were a number of people who made some TeX
materials available for public download, but there was no systematic
collection. At a podium discussion that Joachim Schrod organized at
the 1991 EuroTeX conference, the idea arose to bring together the
separate collections. (Joachim was involved because he ran one of the
largest ftp servers in Germany at this time and had heavily modified
the basic tool
mirror.pl for this purpose.)
CTAN was built in 1992, by Rainer Schoepf and Joachim Schrod in Germany, Sebastian Rahtz in the UK, and George Greenwade in the US (George came up with the name). The site structure was put together at the start of 1992 – Sebastian did the main work – and synchronized at the start of 1993. The TeX Users Group provided a framework, a Technical Working Group, for this task's organization. CTAN was officially announced at the EuroTeX conference in Aston, 1993.
(Note: the familiar Perl archive, CPAN, is based on the CTAN model.)
The US site has moved twice. First, after being at Sam Huston State University under George Greenwade, in 1995 it went to UMass Boston where it was run by Karl Berry. Then, in 1999 it moved to Saint Michael's College in Colchester, Vermont, where it was maintained by Jim Hefferon. In 2011 it left the core CTAN sites.
The UK site at Cambridge has been sponsored by the UK TUG, and was managed by Robin Fairbairns. It left the core CTAN sites in 2015.