E2Guardian - Web filtering solution
Charles Proxy - HTTP proxy / HTTP monitor / Reverse Proxy
ufdbGuard - URL filter for the Squid web proxy
HTTP Toolkit - Beautiful, cross-platform & open-source tools to debug, test & build with HTTP(S). One-click setup for browsers, servers, Android, CLI tools, scripts and more.
NaaS - Nudity-detection as a service run on solar powered Rasp Pi's
Weer - A HTTP protocol debugger with Chrome DevTools frontend interface