AfterLogic WebMail Lite PHP is a free AJAX webmail application. Users can receive, view, manage, compose, and send email through web interface (IMAP and SMTP supported). Source code included.
LuaLB is an open-source parallelizable lattice Boltzmann simulation for computational fluid dynamics with Lua scripting.
Open source SMTP/POP3/SSL e-mail server. Web admin panel, fast and stylish AJAX webmail, secure connections, SMTP authentication, multiple domains, account/domain aliasing, anti-spam, antivirus integration, mailing lists.
Prasi is an authentication framework with full user data management for Perl or PHP web applications. Enabled services can save and share user profile data and can be on different servers. Available in 10 languages, compatible with OpenID.