Wireshark : 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 fac...
HttpWatch : An HTTP Viewer and HTTP Sniffer for IE and Firefox
Bandit : Bandit is a tool designed to find common security issues in Python code. To do this Bandit processes each file, builds an AST from it, and runs approp...
yepnope.js : A Conditional Loader For Your Polyfills!
Vaurien is basically a Chaos Monkey for your TCP connections. Vaurien acts as a proxy between your application and any backend.
You can use it in your functional tests or even on a real deployment through the command-line.