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.
Surge for Mac - Advanced Web Debugging Proxy for Mac & iOS
CCProxy - Want to share Internet connection? Get every computer online through a single Internet connection?
Weer - A HTTP protocol debugger with Chrome DevTools frontend interface
3proxy - 3proxy freeware proxy server for Windows and Unix. HTTP, SOCKS, FTP, POP3
Charles Proxy - HTTP proxy / HTTP monitor / Reverse Proxy