Nov 4, 2009
What are the principal features of the "General Public License" and "Lesser General Public License"?
The General Public License permits anyone to use open source code licensed under its terms. However, it also requires licensees who make modifications to or derivative works of GPL-licensed code to in turn make the source code to their modifications and derivative works available under the GPL as well. The "reciprocity" feature of copyleft open source licenses is probably the single most problematic issue for developers of proprietary software and their investors. In most circumstances, this restriction prevents a company taking GPL-code (or modifications or derivative works of that code) and incorporating it into closed-source proprietary software products. The possibility that the entire source code of a software product would be required to be licensed under the terms of the GPL because it includes a piece of GPL software is seen by VCs and their lawyers as an unacceptable business risk.. To complicate matters, the meaning of the GPL is not always clear, and there have been no U.S. court decisions enforcing it.
