Have you ever tried "The Zero Install system"?

http://zero-install.sourceforge.net/index.html

Code:
Anyone can install software
    You don't have to be root just to install a word-processor.
Anyone can distribute software
    You don't need to be blessed by a distribution (or anyone else) to be part of Zero Install.
It doesn't matter whether software is installed or not
    You just run it. Zero Install handles the rest (downloading and caching as needed).
Downloads are shared
    If one user installs a 20 Mb application, another user can run it without downloading it again.
Users don't need to trust each other
    If one user downloads a malicious program, other users aren't affected.
Here's an example: http://zero-install.sourceforge.net/...html#id2415707