User Agent String.Com 

User Agent String explained :

Mozilla 1.7.12
Mozilla	Name : Mozilla
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
AIX 5.3	Operating System: AIX Version 5.3 (Advanced Interactive eXecutive) UNIX based operating system developed by IBM
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:1.7.12	CVS Branch Tag The version of Gecko being used in the browser For the Mozilla browser this is the browser version as well
Gecko	Gecko engine inside
20051025	Build Date: the date the browser was built
Last visit:	2021.01.17 02:17
All Mozilla user agent strings