Zero Install Injector. LGPL

freshmeat.net: "The Zero Install Injector makes it possible for users to install software easily and without the need for root privileges. It takes the URL of a program's interface description and chooses suitable versions of the program and all of its dependencies (also identified by URLs) according to the user's policy settings (eg. 'stable', 'testing', 'minimal network use', etc). The chosen versions are downloaded and cached and the program is run, using environment variables to let it find the components."