Git Source Code Mirror - This is a publish-only repository but pull requests can be turned into patches to the mailing list via GitGitGadget (https://gitgitgadget.github.io/). Please follow Documentation/SubmittingPatches procedure for any of your improvements.
The official NGINX Open Source repository.
A copy of the Lua development repository, as seen by the Lua team. Mirrored irregularly. All communication should be through the Lua mailing list https://www.lua.org/lua-l.html
Kamailio - The Open Source SIP Server for large VoIP and real-time communication platforms, focusing on flexibility, security and scalability
Rapid spam filtering system.
Dovecot mail server
Cyrus IMAP is an email, contacts and calendar server
The DragonFly Mail Agent, a small Mail Transport Agent (MTA), designed for home and office use.