The GNU General Public License (GPL), created by the Free Software Foundation (FSF), is the most widely used license governing free software and serves as the model for other free-software licenses. The GPL imposes restrictions on licensees not found in open-source licenses, and thus cannot accurately be characterized as an open-source license. In fact, the FSF itself draws this very distinction.
The GPL permits unlimited free use, modification, and redistribution of software and its source code, but imposes three key restrictions on every licensee:
If the licensee redistributes any code licensed under the GPL, it must guarantee availability of the code for the entire work for unlimited replication by anyone requesting it.
If the licensee redistributes GPL code, it may not charge a licensing fee or royalty, but may charge only for distribution costs.
If the licensee includes any GPL code in another program, the entire program becomes subject to the terms of the GPL.
The third restriction mentioned above often is referred to as a "viral" clause, because it causes GPL terms to apply to, or to "infect," software that incorporates or is derived from code distributed under the GPL, regardless of whether the program's developer intended that result or even knew of the presence of GPL code in the program. Violation of these restrictions may subject the offender to civil and criminal penalties for copyright infringement.
Microsoft's View of the GPL
Microsoft supports the freedom of developers to choose their software licensing and distribution models, including the GPL. Microsoft simply wants to advise developers and researchers to be aware of the implications of GPL distribution restrictions before using the license or free software. The GPL is designed to prevent commercial development of software distributed under the license. It does this largely by requiring licensees to make available, at little or no cost, all of the source code for any program that incorporates any amount of GPL code. Given this requirement, commercial developers cannot recover their research and development investments by charging reasonable and appropriate fees for their original software if it uses any GPL code. Free-software developers have every right to pursue this anti-commercial objective.
Microsoft's concern is the resulting degradation of the software ecosystem that would be triggered by widespread acceptance of the GPL, particularly within government and academic research sectors. This ecosystem has sustained unparalleled innovation throughout the industry for the past quarter-century. The principal role of government and universities in the ecosystem is to encourage private enterprises and individuals capable of developing these innovations commercially. Commercial enterprises, in turn, engage in applied research to develop products that advance the state of technology, generating jobs, profits, and tax revenues that boost the economy (funding additional research in the process). Commercial enterprises also disseminate innovations directly into the larger technical-knowledge base.
The combined forces of a well-funded research community and a robust commercial software industry will continue to drive global economic expansion. In the context of basic research, however, the GPL threatens to sever this long-successful partnership.
The GPL and Government Funded R&D
From a research and development standpoint, government-funded research released under the GPL can never be commercialized. The U.S. government has long standing policies that are designed to encourage commercialization of basic research, something the GPL prevents. When public funds are used to support software research and development, the resulting knowledge should be made equally available to all developers, commercial and noncommercial alike. The broad dissemination of research findings in this manner has contributed to a virtuous cycle of innovation in which government funding for basic research, combined with protection of intellectual property rights, creates the foundation for the development of commercial products.