Would automating the install in a script help? http://ursainfosystems.com/blog/automate-the-install-of-openerp-7-0-on-an-ubuntu-vm/ - I think a portable app would be a lot of work - so many dependencies spread in many different directories.

Thanks Ray, in fact it will not be so hard to make a portable app, we can refer to Django Bitnami, it comes with all the dependencies in the same folder : Postgres, Python and MySQL . Django uses only the files and binaries in its folder. So I installed Django to know how it works and how it could use sources repositories to start Postgres and call Python classes, but It is very complicated according to me. A small help will be appreciated.