What is CTAN?
The acronym stands for “Comprehensive TeX Archive Network”, which more-or-less specifies what it's for:
- The archives offer a comprehensive collection of TeX resources. - The content is made publicly accessible, via the internet. - CTAN is a network of archives, which strive to
stay in step with one another.
The basic framework was developed by a TUG working group set up to resolve the (then existing) requirement for users to know on which archive site a particular package might be found.
Actual implementation offers three distinct types of host:
- Core: Perform management functions as well as serving files
- Mirrors: Take regular copies of core archives, and serve them
- Selector: A meta-service, which routes requests
to an apparently "local" mirror ("local" is determined by an algorithm that uses your net address to determine where you are, and then selects a mirror that's close)
Note that there is nothing to prevent any archive from supporting other functions, so a CTAN mirror may also operate as a CPAN (Perl) mirror and as a SourceForge (general free software) mirror, and …
Functions carried out by the core archive are:
- Uploads: users may submit new (or updated) material - Notifications: Significant changes to the archive are reported via the
mailing list <email@example.com>
- Catalogue maintenance - Mirror monitoring
Users may make direct contact with the [CTAN management team](mailto:firstname.lastname@example.org).
Users should ordinarily download material from CTAN via the archive selector: this uses the mirror monitor's database, and uses the caller's geographical location to offer an efficient choice of “sufficiently up-to-date” mirror site for you to connect to. This procedure has the advantage of distributing the load on CTAN mirrors.
Source: What is CTAN?