There is little doubt that GNU General Public License (GPL) is not only the most used but also the most controversial Free Software license. While it gives users the freedom to use and study programs, it does not give them freedom to do whatever they want with derivative works. In fact, GPL is incombatible with many Open Source licenses.
Now MySQL has published a solution to GPL-incompatibility problems. Basically they have added an exception saying that code under GPL can be combined with code under any other Open Source compliant license. Technically speaking, MySQL users have an option to choose either a “plain GPL” or the amended, more Open Source friendly, version. Free Software Foundation currently classifies Free Software licenses according to their GPL compatibility, which in my opinion just confuses people. MySQL’s new policy is an example of an attempt to make information, and software in particular, available to all with no artificial (whether they be commercial or ideological) constraints.