A discussion of hybrid open source and proprietary licensing models.

[Marshall Van Alstyne <marshall AT MIT.EDU>]

Based on discussion here, I contacted Zack Urlocker, VP of MySQL and got
the following back with permission to post:

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I'm always interested in ways
that licensing could be more effective.   I think the GPL is a
very good license (that's why we use it) but of course it was written for
a specific purpose at a point in time and I think things have changed a
bit over the years.  Our philosophy or approach is different from
the FSF in that we recognize that there is a case where a non-open source
license makes sense.  We have some customers, like Cisco, SAS etc,
who like our product but don't want to abide by the GPL, and so that's
why we offer the dual license approach.  We summarize our philosophy
as "Quid Pro Quo"  to mean that if you're free, we're
free, and if you're closed source, we have a commercial license. 

As has been noted on your discussion boards, there are challenges with
the dual license approach.  I wonder if it would be possible to have
a single license that meets the needs of a commercially sustained open
source development effort, like MySQL.  There are other companies
that also use the dual license approach, like Sleepycat, Trolltech, OSAF
etc.

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