Shared source

Shared source is a term popularized by Microsoft to mean basically a vendor-controlled consortium with conventions and agreements almost as strong as mandatory patent licensing, but in fact relying solely on that one vendor's judgement. It claims the primary advantage of being self-funding while free software and much open source are not, relying on what Microsoft calls 'unsustainable' donations and volunteer effort exclusively.

One legitimate place where shared source seems to beat all other license models is in usability - the most popular user interfaces in the world come from Apple and Microsoft and are exactly this kind of tightly vendor-controlled pseudo-consortium, using patent, trademark and copyright all quite strongly to ensure that there is no bad copy problem in the GUI.

For instance, if you ship a Windows application without "File, Edit, View..." on the menu line, have fun trying to call it Win-anything...