Mozilla Firefox browser is now also available in 64-bits build for windows. The 64-bit build for Linux and Mac is already available. The 64-bits version is not officially released by Mozilla, and is currently in pre stage. The current version is Firefox 3.7 pre which will actually become Firefox 4.0
New Features available in 64-bit Firefox for windows are:
I will not suggest you to use the browser now as your main browser as it has many bugs and may have lots of problem. It is also said that it eats lots of memory. Other reason for avoiding 64 bits Firefox browser for now is non-availability of 64-bits supporting plugins. Firefox browser users are largely dependent on its plugins. But you must give it a test try.
For now, you can download the 64-bit Firefox from Mozilal FTP server.