It has some specially-selected optimizations to make it perform faster and extend the life of your USB key as well as a specialized launcher that will allow most of your favorite extensions to work as you switch computers. It will also work from a CDRW drive (in packet mode), ZIP drives, external hard drives, some MP3 players, flash RAM cards and more.

This release updates the bundled Mozilla Firefox to 2.0.0.8, fixing some known security issues. The launcher and installer were also updated to add some new features and abilities:

Automatic Local Homepage Handling - If you use a homepage (or multiple homepages in tabs) on your portable device, Firefox Portable will automatically update them to work as you move between PCs

Improved Paths Handling - The directory paths in your preferences file are now automatically updated, making it easier to select local directories for downloads. This also allows some non-portable extensions to now work with Firefox Portable (FlashGot, some GreaseMonkey customizations, Sage CSS skins, etc).

Digital Signatures - The launcher and installer are digitally signed, so you can be sure they're the official releases and haven't been modified.