In the early days of computer, software is self contained in its own directory. When you need to upgrade the computer, just copy the directory to the new harddisk and you are back to business right away. Then comes Windows, software is chopped up into bits and pieces and the data is hiddened somewhere inside the registery and application data. That makes moving the directory of the software a nightmare since you have no idea what stuff you need to backup. If you don’t have to adminstrater privilage in the computer, you can’t even install the software since you have no write access to the registery file. It only make software more inconvinient to use. Finally, someone had enough with this stupid idea of registry and port many commonly used opensource software tp a portable version. You just have to download the software package from their website, unzip the files into the directory and you are ready to go. You can copy the files from one hard disk to another and use the software without any problem. It is good to have a copy of your commonly used software stored in a USB drive for carry around and in case of emergency. I can also get around of the installation limitation of the Critix account at work to install Firefox. The portable applications can be downloaded here.