A good post from the CTO at Alfresco (and founder at Documentum) explaining the origins, business model and purpose of commercial open source – including the role of large commercial vendors in the history of open source. He also make a good point that:
“Professional open source works well when enterprise software is commoditized. Alfresco was created because of the increasing difficulty in differentiating one enterprise content management system from another.”.
If you think quality, enterprise grade open source software is as simple as ‘free software’, you need to read this.