A portable app is a computer program that you can carry around with you on a portable device and use on any Windows computer. When your USB flash drive, portable hard drive, iPod or other portable device is plugged in, you have access to your software and personal data just as you would on your own PC. And when you unplug the device, none of your personal data is left behind.
Firefox Portable is a repackaged version of Firefox designed to run from a USB flash drive, iPod, external hard drive or other portable media. It arose out of a mozillaZine thread in June of 2004. John T. Haller released the first packaged version and has led its further development. It includes a specialized launcher that adjusts extensions and themes to work as it is moved from different computers. There is also a portable version of Firefox available for Macintosh computers called Portable Firefox OS X.
Download updated portable app version here.
This is necessary download for USB device.