Open Source Software: What Is It and How Does It Work? - By Dr. Ben Kremer (Groklaw)
Groklaw republishes
an essay by Dr. Ben Kremer on open source and the GPL. "
The hardest conceptual problem about open source software is how to ensure people play by the rules. There are many models, but the most common is to require any person who redistributes an open source program (whether in its original form, or with any changes they have made) to also redistribute the accompanying source code."