CTAN

CTAN, the Comprehensive TeX Archive Network, is a distributed archive of TeX-related material, including macro packages, fonts, documentation, and utilities for TeX, LaTeX, and related systems. It serves as the primary repository through which the TeX community publishes and distributes software and documentation.

CTAN is operated as a network of mirrors around the world. The central portal, ctan.org, provides package indexing, metadata, browsing, and links to the various mirrors. Access to CTAN is available via a web interface as well as file transfer methods such as FTP and rsync, allowing sites to synchronize their copies of the archive.

Package organization is by hierarchical directories and categories, with each package containing its files and a readme. Maintainers submit updates to CTAN; editors review submissions for quality and completeness before they are accepted. Once approved, updates propagate through the mirror network, ensuring broad availability.

CTAN has played a central role in the TeX ecosystem since the 1990s, serving as a widely used source of macro packages, fonts, documentation, and tools. Many TeX distributions and package managers rely on CTAN as a reference repository for software to include or fetch for installation. The archive emphasizes long-term accessibility and documentation, making it a key resource for TeX users and developers.