The Impact of the GPL
So what effect has the GPL had on software development and the open source movement as a whole? It's actually had a tremendous impact.
First, many very common UNIX applications, such as GNU Emacs, have been released under the GPL, and are used by countless numbers of users every day.
Second, the open source software movement has taken several ideas promoted by the GPL and modified them slightly. The most important is the idea that software licensing should include access to source code. As we move into a more complex era of computing, this issue becomes important for multiple reasons:
Stability and longevity. If your company invests in a proprietary software package for a mission-critical task, and the company that sold you the software subsequently goes out of business, what do you do? It might mean scrapping a large-scale deployment, which can be very costly. However, with source code, you could have internal company developers charged with maintaining the application, fixing bugs, and even developing new features.
Security. By being able to review the source code, you can be certain that a mission-critical application is secure and doesn't contain any backdoors or other potentially devastating security flaws.
These are just a couple of reasons that have caused many people to advocate the inclusion of source code in software distribution.
However, some developers want to distribute source code, but don't want to forgo all distribution rights, as would be required under the GPL. As a result, there have been a host of competing open source licenses: the Apache License, the BSD License, the IBM Public License, the Sun Public License, and the QtPublic License, to name just a few. The Open Source Initiative (OSI) reviews licenses for compliance with the goals of open source, and publishes approved licenses on the OSI web site.
There is even an effort to create open source or copyleft-style licenses for creative content, such as writing, video, Flash animations, etc. This effort is spearheaded by the Creative Commons, which has a number of different licensing options available to the creative community.
The bottom line is that the GPL and licensing agreements from the open source community aren't a panacea for protecting individual liberties, and they're not an affront to the free market and the protection of intellectual property. They're simply another tool that developers have in their arsenal to control how they would like the software they create to be used.