Is the Minix 3 license GPL compatible?

Question

Does anyone know if Minix 3's license is GPL compatible? It's a BSD-style license, but I'm not entirely sure if it's compatible with the GPL.

Here is a link to the license: http://www.minix3.org/other/license.html

Answer 1

Here is the MINIX 3 license:

License

Copyright (c) 1987, 1997, 2006, Vrije Universiteit, Amsterdam,
The Netherlands All rights reserved. Redistribution and use of the MINIX 3
operating system in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

    * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.

    * Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in the
    documentation and/or other materials provided with the distribution.

    * Neither the name of the Vrije Universiteit nor the names of the
    software authors or contributors may be used to endorse or promote
    products derived from this software without specific prior written
    permission.

    * Any deviations from these conditions require written permission
    from the copyright holder in advance


Disclaimer

 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS, AUTHORS, AND
 CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
 NO EVENT SHALL PRENTICE HALL OR ANY AUTHORS OR CONTRIBUTORS BE LIABLE
 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

The first three clauses are exactly those of the BSD 3-clause license, which is compatible with the GPL. The fourth clause is redundant, any other use is copyright violation unless explicitly permitted by the copyright holder. So the MINIX license is GPL-compatible.

Answer 2

The Minix 3 license looks very similar to a standard BSD style license which is more permissive than the GPL, for example it will allow commercial use of the software in binary form without forcing a release of the source code.

It is considered free software (like any of the BSD software), but is not compatible with the GPL mainly due to the "advertising clause". The GPL tends to be more restrictive. In other words while the GPL does allow commercial use of the software it does force the release of the source code under the GPL now and in the future (for anybody who modifies it further). BSD style licenses allow release of a binary version of the software with no source whether it is unmodified or has been modified further.