GPL and commercial licensing, Amphora product

[Jüri Kaljundi]

May be some of you can help with this, or direct to someone who can. The question is about using GPL licenses for software, that at the same time is licensed commercially. 

Our company is the manufacturer of Linux/Zope/Python/PostgreSQL based groupware/document/project management software package called Amphora(http://www.amphora.ee/eng/). The free version (Amphora Light) which includes the core and has only groupware functionality (http://www.amphora.ee/freeware/) is currently licensed under Mozilla type license. Then we have an extended version, which has CRM, project management and document management modules, that we sell as a standard software package and that is not free software. 

What we would like to do is to make potentially the free Amphora Light license a bit more relaxed, and for that we have considered starting to use the GPL License for the freeware version. The question is that we still would like to keep selling the full version, which is based on the free version. Do I understand it correctly, that under GPL license we could not do that, and the full commercial version would also have to be free in case it includes any GPL code? 

Or can we as the copyright holder still use the GPL product code in our full version by initially double-licensing it?

How is MySQL doing it? They say they use GPL license, but they do not allow commercial use or packaging with commercial products? 

With best regards,

Jüri Kaljundi
IT Meedia
jk at itmeedia.ee
http://www.itmeedia.ee/
GSM tel: +372-5015252

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