Planeshift is not in compliance with the GPL.

The GPL (http://www.gnu.org/licenses/gpl.html) can\'t be linked with another proprietary license, such as the Planeshift License.  GPL-covered software can\'t depend on proprietary modules, such as the art, models, music, texts, names, setting, etc. Specifically, it would not be legal to distribute the GPL-covered parts of Planeshift with these proprietary pieces.

These problems go away if your source code is released under the Lesser General Public License (http://www.gnu.org/licenses/lgpl.html). The LGPL is intended for software that can be linked with proprietary pieces. Crystal Space is released under such a license, so anyone can use it, even proprietary software pieces such as Planeshift.

I think it would be better if the PlaneShift team made clear that Planeshift as a whole is in fact *proprietary software.* Your current web page (http://www.planeshift.it/download_source.html) is very misleading; it describes the philosophy of open-source/free software. This philosophy says that the receiver of a piece of software should be able to use it for any purpose they would like, including modifying and redistributing it (http://www.gnu.org/philosophy/philosophy.html#AboutFreeSoftware and http://www.opensource.org/docs/definition.php). The PlaneShift team asserts that the open-source/free software philosophy is not viable for building a game of this type (http://www.planeshift.it/pslicense.html), therefore, they use a proprietary license. Which is fine: the PlaneShift team has the right to decide upon their own license terms. What is not fine is pretending that Planeshift is open-source/free software. The LGPL\'ed covered parts are, but they don\'t do much without the proprietary pieces.

I hope the PlaneShift team takes these issues seriously.

Keep in mind, I have no hard feelings towards the PlaneShift team. They seem to be making a fantastic MMORPG. I look forward to playing it, proprietary software or not.