http://www.opensource.org/node/196Interestingly enough, I think an OSI champion (Michael Tiemann) said it perfectly:
One of the questions we received during the interview was the question "What's the difference between the Free Software Foundation and the Open Source Initiative?" I chose to answer the question based on the constituencies of free software and open source. In my view, the fundamental difference between the free software movement and the open source movement is that free software is based on the ethics of software freedom, and open source is based on pragmatic implementation of observed results.
Perfect! Free software is based on the ethics of software freedom, and open source is based on pragmatism. I love both movements but my heart belongs to the FSF. Show me a measure of "pragmatism" that insists on the violation of personal freedom and I'll show you the door
