...The main idea is to bring a distro-independent version that can be carried around, and ran on some major Linux distributions without having to worry about compatibility.
The apps are built using AppImageKit, brought by PortableLinuxApps:
http://portablelinuxapps.org/docs/1.0/AppImageKit.pdf
The clients are built on Xubuntu 12.04 32-bits using a Live USB.
All clients will be tested on Ubuntu, Xubuntu, Fedora and OpenSUSE 32-bits.
If you're curious about what's inside the *.run files, you can use AppImageExtract:
https://sourceforge.net/projects/portable/files/AppImageExtract/download
If you want to improve/modify/fix a package you can use AppImageKit to rebuild the package yourself.
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