Sometime people things to get back the settings of software they used last time on another computer. Sometime installing OS means lost the Settings made in Firefox and Chrome browser.
portableapps.com provide the portable version of software which you can backup and able to use them on another computer without loosing any settings.
This way you never lost History,plugins and custom settings you have applied in Firefox,chrome & skype.
Portableapps is better way to run software. It’s not make any Registry on computer. You can backup your software with Settings and able to use them on another computer without doing same settings again and again.