Powerful, enterprise-ready, open source web server w/ automatic HTTPS
Anti-Spam SMTP Proxy Server implements multiple spam filters
Encrypted UDP based FTP with multicast
Proxy Cache and Web filtering Appliance
Reverse proxy with http header, html and javascript code rewritter
Turn any program that uses STDIN/STDOUT into a WebSocket server
Reverse proxy with website translation
Squidgate is a webinterface to manage squid
Microsoft Exchange compatible server and client libraries