FirePHP is absolutely great. Even better is that multiple languages are getting libraries for the protocol underlying FirePHP: Python with firepy: http://code.

FirePHP is absolutely great. Even better is that multiple languages are getting libraries for the protocol underlying FirePHP: Python with firepy: http://code.google.com/p/firepy/wiki/Documentation http://code.google.com/p/firepy/wiki/Documentation Ruby/Rails with rails-firephp: http://rubyforge.org/projects/rails-firephp/ http://rubyforge.org/projects/rails-firephp/ Perl in typical fashion with several modules: http://search.cpan.org/search?query=FirePHP&mode=all http://search.cpan.org/search?query=FirePHP&mode=all There's even a patch for Apache's mod_rewrite: http://www.firephp.org/Wiki/Libraries/ModRewrite http://www.firephp.org/Wiki/Libraries/ModRewrite There's also documentation about the protocol if you need/want to build your own: http://www.firephp.org/Wiki/Reference/Protocol http://www.firephp.org/Wiki/Reference/Protocol I find it a very useful development aid. I'm just hoping more browsers (well, my preferred browser) start having something that can interpret the FirePHP stuff :-)