In this blog post I will try to answer some of the most common questions I have heard during the last week:
A. Can MySQL be killed?
1. The easiest way to kill MySQL would be to not sell licenses any more or make their prices 'really high'.
2. Another scenario is that the development resources are drastically reduced in some important areas. Then people would stop believing in the future of MySQL, which slowly will kill the product. Especially if the present license is in place. (Remember that most of the development of the core of MySQL is done by the developers at SUN, not by a large community)
B. "But anyone can fork it!"
One can fork a GPL project (i.e. the code), but one can't easily duplicate the economic infrastructure around it.
MySQL is not an end user application, but an infrastructure project that is quite deep in the system stack. Most of the technology partners, where most of the innovation in the MySQL space happen nowadays, depend on being able to get licenses for MySQL so that they can combine their closed source application or closed code (like storage engines) with MySQL. If you take the license revenue and add it to all direct and indirect money that comes from these kind of partners, this is a huge part of the MySQL economic infrastructure (i.e., where the money is).
A fork of an infrastructure GPL project can't work with any of the above mentioned partners and the fork can't be used by anyone who needs to distribute it with their own closed source parts or use it with others closed source parts. If there would be no way for partners to combine their code with MySQL, these partners and users would have to put their efforts on some other project and the money flow and a big part of the innovation around MySQL would stop. Over time other projects that allow everyone to participate and make money will take over the MySQL business.
It's possible to create companies doing support for MySQL, but without the economics, there will not be enough money and incentive to pay enough for the development of MySQL to satisfy the requirement of all the MySQL users. Any such company will just make MySQL 'die slower', but not be able to save it.
The simple fact is that keeping a project like MySQL alive and having it compete with big vendors like Oracle, require many people working in it. If they can't get any revenue from doing that (except support revenue, which is not enough), you will find very few companies prepared to do development and extremely few (or none) investment company would put serious money on a company that gets all of it's money on services (not scalable).
Another thing, like Richard Stallman pointed out, is that MySQL is only available under GPL2 and can't be combined with GPL3 code. This means that new Free software projects that uses GPL3 can't use MySQL. This is a problem, but less severe than the problem of economics.
C. "Is GPL not a good enough license?"
I think that GPL is a fantastic license. It ensures that projects under the GPL are kept free. At the same time it allows companies that wants to participate in Open Source to make enough money to be able to develop the product full time. GPL ensures that these companies can keep tight control on the product and especially on their (closed source) technology partners. This is why investors are interested to invest in companies that use GPL; They know that no one can just come and fork the product and take everything away from company that holds the copyright to the code.
It's safe to assume that both Sun and Oracle understand this. This is why Sun bought MySQL for a high valuation and this is why Oracle doesn't want MySQL to be divested.
If it would be easy to take over MySQL by just forking it, Sun would never have bought MySQL and Oracle would have forked MySQL a long time ago instead of now trying to buy it as part of the SUN deal.