User Agent String explained :
|  Firefox 3.5.9 | |
|---|---|
| Mozilla | MozillaProductSlice. Claims to be a Mozilla based user agent, which is only true for Gecko browsers like Firefox and Netscape. For all other user agents it means 'Mozilla-compatible'. In modern browsers, this is only used for historical reasons. It has no real meaning anymore | 
| 5.0 | Mozilla version | 
| Windows | Platform | 
| U | Security values: 
 | 
| Windows NT 6.0 | Operating System:  Windows Vista | 
| nl | Language Tag, indicates the language for which the client had been localized (e.g. menus and buttons in the user interface) nl =  Dutch | 
| rv:1.9.1.9 | CVS Branch Tag The version of Gecko being used in the browser | 
| Gecko | Gecko engine inside | 
| 20100315 | Build Date: the date the browser was built | 
| Firefox | Name :  Firefox | 
| 3.5.9 | Firefox version | 
| .NET CLR 3.5.30729 | .NET framework Version : 3.5.30729 | 
| First visit: | 2010.05.31 12:22 | 
| Last visit: | 2018.07.28 08:52 | 
| All Firefox user agent strings | |