Fiddler Web Debugging Proxy 2.3.0.0 Beta
Fiddler is a Web Debugging Proxy which logs all HTTP(S) traffic between your computer and the Internet. Fiddler allows you to inspect all HTTP(S) 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.
Fiddler is freeware and can debug traffic from virtually any application, including Internet Explorer, Mozilla Firefox, Opera, and thousands more.
Changelog:
Fiddler 2.3.0.0 [7/23/2010]
Support for Regular Expressions in more places
Improved Compare Sessions feature
Firefox 4.0 compatibility for FiddlerHook
Various bugfixes
Changelog Beta Version: http://www.fiddler2.com/Fiddler2/newbeta.txt
Changelog Final Version: http://www.fiddler2.com/Fiddler2/new.txt
BBS: http://groups.google.com/group/httpfiddler
Homepage: http://www.fiddler2.com/fiddler2/ | http://www.fiddler2.com/fiddler2/version.asp