I just check for many projects for portable apps...
I saw http://appimage.org/ project. It is open source: https://github.com/probonopd/AppImageKit It seem good. The packAges does not work on every Linux dist. But it desisgn for many major Linux distros. Thats a good idea.
But I did not see the source code of portable app packages, or any video on youtube... Is there anyone who use them on this forums? or any comment about this project?