User Agent String.Com 

User Agent String explained :

Netscape 9.0
Mozilla	It's a Mozilla based browser
5.0	Mozilla Version
X11	X Window System a windowing system for bitmap displays
U	Security values: N for no security U for strong security I for weak security
Linux i686	Operating System: Linux running on a Intel Pentium Pro CPU
en-US	Language Tag, indicates the language for which the client had been localized (e.g. menus and buttons in the user interface) en-US = English - United States
rv:1.7.5	CVS Branch Tag The version of Gecko being used in the browser
Gecko	Gecko engine inside
20070321	Build Date: the date the browser was built
Netscape	Name : Netscape
9.0	Version
Last visit:	2008.07.27 04:57
All Netscape user agent strings