Subject: Re: Free Software vs. Open Source
Date: Mon, 18 Feb 2002 10:08:43 +0000


> > What is your opinion about the business model used by companies
> > like Trolltech (Qt) and Sleepycat (Berkeley DB), which provides
> > both copylefted and proprietary versions of same software?
> [snip]
> I would not use this method this myself, for two reasons: 1. I think
> it is more upright to make the same terms for everyone, not sell
> exceptions.  2. Selling exceptions to a copyleft license like the GPL
> reduces the pressure it can exert for others to make their software
> free as well.

A snippet from an interesting interview with Sleepycat's Michael Olson.

    "This works for two very important reasons. 

    "First, Berkeley DB is a library. In order to use it, developers
    must link it with their applications. That gives us leverage over
    the terms under which the embedding application is distributed. We
    can force them to use an open source license or to pay us money.
    This strategy doesn't work for standalone applications like Web
    servers, relational database servers, or mail servers, because the
    end user doesn't change those or link directly with them. Note also
    that this wouldn't work if we applied something like the LGPL to
    Berkeley DB -- it's only the full-blown GPL-style license we have
    that gives us the leverage to charge money."

Are there any examples of a program being deliberately warped to
contain a library component so that it gains this benefit of a
GPL-style licence?