[dredmorbius]

It was open-source, MIT/BSD-licensed reference implementations of X11, email and Web servers which helped hugely to promote the adoption of these protocols.

It was the mere hinting by the University of Minnesota that it might consider proprietary licencing of the gopher protocol that killed it dead. Numerous other protocols have been pitched but as proprietary solutions, never to see widespread acceptance. Sun's NEWS display system, and numerous HTML also-rans particularly come to mind.

Even the FSF, which strongly encourages GPL and APL licencing to spread the concept and use of Free Software acknowledges and encourages the use of "permissive" licencing -- MIT, BSD, and LGPL -- to encourage adoption of open protocols and infrastructure (glibc and other libraries).