If you develop and distribute a commercial application and as part of utilizing your application, the end-user must download a copy of MySQL; for each derivative work, you (or, in some cases, your end-user) need a commercial license for the MySQL server and/or MySQL client libraries.
I don't know how MySQL get away with saying the above, because what they are saying is rubbish. Why can't another person download a copy of MySQL when it's GPL'd. I suppose it's the terms you except when you use it. That's why I use PostgreSQL, and for other obvious reasons.
MySQL is talking out of their ass :-) The only restrictions under the GPL are on destributing derivative works - according to the GPL itself, linking falls under that, but you don't link against the mysql server directly - you typically link against the mysql client library. My guess is that that's why they changed the client lib's license from LGPL to GPL on version 4. If you use libmysql 3 or write your own client lib, you have no obligations under the GPL. In any case, whether or not the client has to download mysql doesn't effect the licensing terms. Also, the term "commercial application" is (probably deliberately) vague and confusing.

"What should it profit a man, if he should win a flame war, yet lose his cool?"

In reply to Re^5: Protecting our work by Joost
in thread Protecting our work by bradcathey

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