Mac OSX, FF, Safari, Opera
peecee windoze XP just for testing: FF, Internet Exploder (standards? what´s that?), Opera.
PS: don´t forget Opera, nowadays it has about 7-8% marketshare and growing! This is probabilly the most precice and sensitive browser of all! Also almost all mobile internet surfing gadgets are utilizing opera´s technology.
FF´s growth has become very slow, grew maybe 5% in the last 2 years.