Plus QA

1991 WorldWideWeb (Nexus)
1992 ViolaWWW, Erwise, MidasWWW, MacWWW
993 Mosaic, Cello, Lynx 2.0, Arena, AMosaic 1.0
1994 IBM Web Explorer, Netscape Navigator, SlipKnot 1.0, MacWeb, IBrowse, Argo, Minuet
1995 Internet Explorer, Netscape Navigator 2.0, OmniWeb, WebRouser[3], Internet Explorer 2, Grail
1996 Arachne 1.0, Internet Explorer 3.0, Netscape Navigator 3.0, Opera 2.0,PowerBrowser 1.5[4], Cyberdog, Amaya 0.9, AWeb, Voyager
1997 Internet Explorer 4.0, Netscape Navigator 4.0, Netscape Communicator 4.0, Opera 3.0
1998 Internet Explorer 5.0 Beta 1, iCab, Mozilla
1999 Amaya 2.0, Mozilla M3, Internet Explorer 5.0
2000 Konqueror, Netscape 6, Opera 4, K-Meleon 0.2
2001 Internet Explorer 6, Galeon 1.0
2002 Netscape 7, Mozilla 1.0, Phoenix 0.1, Links 2.0
2003 Opera 7, Safari 1.0, Epiphany 1.0
2004 Firefox 1.0, Netscape Browser, OmniWeb 5.0
2005 Safari 2.0, Netscape Browser 8.0, Opera 8, Epiphany1.8, Amaya 9.0, AOL Explorer1.0, Maxthon 1.0, Shiira 1.0
2006 SeaMonkey 1.0, K-Meleon 1.0, Galeon 2.0, Camino 1.0, Firefox 2.0, Avant 11, iCab 3, Opera 9, Internet Explorer 7, Sputnik
2007 Maxthon 2.0, Netscape Navigator 9, NetSurf 1.0, Flock 1.0, Safari 3.0, Conkeror
2008 Konqueror 4, Safari 3.1, Opera 9.5, Firefox 3, K-Meleon 1.5, Amaya 10 (est.) Beta Internet Explorer 8, Flock 2.0, Safari 4.0, Google Chrome

Source: wikipedia.org

OS Platform Statistics:
Windows XP => 73.3%
Windows Vista => 13.2%
Windows 2000 => 2.2%
Windows 2003 => 1.8%
Windows 98 => 0.2%
Linux => 3.8%
Mac => 5.2%

Browsers Statistics:
IE7 => 26.3%
E6 => 22.3%
Firefox => 42.6%
Mozilla: 0.5%
Safari => 2.7%
Opera => 2.0%
Chrome => 3.1%

Source: http://www.w3schools.com/