Firefox: 50000000
Firefox is celebrating 50 million downloads now 
I have been using it for a long time now, it is quite neat and fast. You don’t have to worry about IE security holes and non-standard M$ tags anymore.
BTW, this is a test post using BlogJet. The only thing I found annoying with this desktop blog publishing tool is that it has poor support for encoding, e.g. I cannot post Simplified Chinese contents 
