Even if it would be nice we cannot consider possible to put everything inside Phabricator (rewriting all needed applications).
It would be nice to have a simple way to adapt already existing (external) ones or even not to adapt but simply display them inside a Panel, passing at least one way some basic information as the user profile (via for example a "get context" service or HTTP variables).
There is some possibility?
(my specific case is now for example the willingness to include some Pinterest like application, but the question is anyway more generic)