Outside of the regular Mozilla Firefox, you can also get optimized versions that are designed to work with your particular processor. The link below also has freeware links.
http://www.moox.ws/tech/mozilla/
I personally love MOOX's M2 Build of FireFox. Solid as a rock. Eagerly awaiting M2 based on the final FireFox 1.01.
BTW: I didn't see links for the freewares "VobBlanker" and "IFoEdit" posted here.