The purpose of open source and free software licensing is to permit and encourage the involvement by licensees in improvement, modification, and distribution of the licensed work. This open development model of software development is the unique strength of the open source and free software movement. While the open source and free software licenses already discussed approach open software development differently, open development is the goal.
This chapter describes the basic principles of software development under open source and free software licenses, including the problems of forking, community development under the bazaar and the cathedral models, how open source and free software projects are initiated and maintained, and the effect that license choices can have on software development. This chapter also briefly discusses the basic principles of drafting contracts, for those who are interested in drafting their own software license.