Hey, when I visit this site,
http://tools.whois.net/browser/

it tells me that IE 7 is,
Your Browser Information is:
Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 2.0.50727; .NET CLR 1.1.4322; .NET CLR 3.0.04506.30; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022)


Why does IE report 'Mozilla' at the beginning of the string? I notice FireFox 2/3 reports "5.0" instead of 4.

Whats it all mean?! I thought mozilla came after IE so why do they report themselves as mozilla.

All browsers do this. It's so it can get web content designed for Netscape.

Historical reasons.

Back then Netscape was the best, IE included the Mozilla version to trick browser detection code into thinking it was based on Mozilla. Now it's the reverse (Except IE isn't the best), Opera used to say it was IE for a while, and Safari says it's "Like Gecko" to trick code searching for Gecko.