HttpWatch : An HTTP Viewer and HTTP Sniffer for IE and Firefox
Buildbot : Buildbot is an open-source framework for automating software build, test, and release processes.
BeEF : The Browser Exploitation Framework (BeEF) is a powerful professional security tool. BeEF is pioneering techniques that provide the experienced penetra...
Sitespeed.io : Sitespeed.io is an open source tool that helps you analyze and optimize your website speed and performance based on performance best practices. It col...
Wireshark is the world's foremost network protocol analyzer. It lets you see what's happening on your network at a microscopic level. It is the de facto (and often de jure) standard across many industries and educational institutions.