X-Firefox is a totally portable version of Firefox, Mozilla's popular open-source Web browser. Mozilla's core underpins many Firefox rivals, offering Firefox-like functionality with individual touches. But X-Firefox isn't a Firefox clone or wannabee; it's Firefox, the whole kit and caboodle, just rendered portable. It functions in nearly every way like the installed version of Firefox, only it runs from a different location, one that can be a USB drive or other external storage device. With X-Firefox, you can carry your personalized browser with you and run it on different machines without having to customize each Firefox installation. X-Firefox is available in two Firefox releases, 3.6.2 and 6.0. Both worked well in our tests, but we focused on the version of X-Firefox based on the latest release, Firefox 6.
Before we installed X-Firefox, we uninstalled our standard copy of Firefox, which isn't necessary but made for clean testing. The process for downloading and setting up X-Firefox differs from the usual Firefox installation procedure, but since it's largely automatic, there's no point in dwelling on it, though the installer explains it all for the curious. Basically, X-Firefox starts the browser normally in "silent" mode and then transfers files that enable it to run independently of the Windows installation. To test X-Firefox's portability, we closed the browser and moved its folder to the desktop. We clicked the program's executable file and then clicked Run on the Open File dialog. X-Firefox opened normally: portability proved. We closed and reopened the program, this time deselecting the Open File verification stage. Subsequently, X-Firefox opened immediately when we clicked its program file. We clicked About Firefox in the Help menu and verified that we were indeed running the latest version of Firefox, release 6.0.
As near as we can tell, X-Firefox functions exactly like the version installed on millions of PCs worldwide, but you can carry it around with you, which lets you use your bookmarks and other personalized settings on any compatible Windows machine. Users who need a tried-and-true version of Firefox can download the previous X-Firefox release.