I've you want to use mySQL-server for non-comercial purpose it is free for you!
Original answer to these subject form
mySQL-Team:
Here you get extensive license information. What you need for
educational purposes is our latest development version 3.23.x, which
is free.
MySQL Unix 3.23.x and the Win32 3.23.x versions are now
under the GPL license so you only need a license if:
- You link a part of the of MySQL that has a GPL Copyright to a program
which is not free software (embedded usage of the MySQL server). In
this case your application would also become GPL through the clause in
the GPL license that acts as a virus. By licensing MySQL from us under
a commercial license you will avoid this problem.
- You have a commercial application that ONLY works with MySQL and ships
the application with the MySQL server. This is because we view this a
linking even if it is done over the network.
- You distribute MySQL and you don't provide the source code for
your copy of the MySQL server, as defined in the GPL license.
You can find the latest development version at
http://www.mysql.com/downloads/mysql-3.23.html.
The 3.22.x stable version is still under the old more restrictive
license (Win32 3.22.x is fully commercial product and only available
for paying customers) and you need a license if:
- You sell the MySQL server directly or as a part of another product or
service
- You charge for installing and maintaining a MySQL server at some client
site
- You include MySQL in a distribution that is non redistributable and you
charge for some part of that distribution
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