Alternative to Firebug for Firefox?

Firefox now has built in developer tools similar to Firebug, but not so full-featured:

https://www.mozilla.org/en-US/firefox/technology/

http://www.webmonkey.com/2011/12/an-overview-of-firefoxs-coming-developer-tools/

Fidler Web Debugger is an option, although it's not as integrated.

Other alternatives include:

• Jash: Javascript Shell
• Internet Explorer Developer Tools
• FireAtlas (extension to FireBug, but helps debug ASP.NET)