“AMONG all the hype surrounding the rise of Open Source, the
humble origin of the movement is often lost. In fact, a simple
legal document gave birth to the current situation.”
“That document is the General Public Licence (GPL), otherwise
known as “copyleft”, and it has engendered a variety of imitators
which are being accepted on their own terms.”
The GPL is the most generous and rigorous of the intellectual
property protections that seek to allow programmers and users to
benefit from the collaborative efforts of a group. Strictly
speaking, the GPL falls into the category of Free Software, not
Open Source, although much of that latter movement is derived from
the former.”