Web Design Tools
Fiddler Web Debugger - A free web debugging tool
What is Fiddler? Fiddler is a Web Debugging Proxy which logs all traffic between your computer and the Internet. Fiddler allows you to inspect traffic, set breakpoints, and "fiddle" with incoming or outgoing data. Fiddler includes a powerful event-based scripting subsystem, and can be extended using any .NET language.