Squid Proxy - Website Content Acceleration and Distribution. Thousands of web-sites around the Internet use Squid to drastically increase their content delivery. Squid can reduce your server load and improve delivery speeds to clients.
CCProxy - Want to share Internet connection? Get every computer online through a single Internet connection?
Polipo - A small and fast caching web proxy (a web cache, an HTTP proxy, a proxy server).
3proxy - 3proxy freeware proxy server for Windows and Unix. HTTP, SOCKS, FTP, POP3
AdGuard - Surf the Web Ad-Free and Safely. Shield up!
Apache Traffic Server - Fast, scalable and extensible HTTP/S 2 and 1.1 compliant caching proxy server.