Something that legally prohibits this falls outside the definition of open source. Dual licensing with part of it not available as open source can fulfill your need although many including me somewhat dislike that and consider that against the spirit of open source. The GPL prevents people from modifying/distributing modified source without releasing the source and is highly disliked by a number of companies who would have nothing to do with it. They can still use it without distributing it like on a server without releasing changes as open source.