[Sharlin]

MS used to bundle a similar WYSIWYG editor with IE as well, Frontpage Express (a stripped-down version of the commercial MS Frontpage).

[nommm-nommm]

Well a WYSIWYG editor built in is not really comparable with the features of Firebug.

[Sharlin]

Sure, but Netscape Composer was a WYSIWYG editor as well, not a web page inspector/debugger like Firebug. Honestly, there was not much to inspect or debug in web pages at the time...