Licensing Explained
The license for all the items in Gluon itself (that is, GluonCore, GluonGraphics, GluonInput, GluonAudio, Gluon Creator and the various Gluon Player applications) is the GNU Lesser General Public License, version 2+ (LGPLv2+).
Game Licenses?
While the Gluon libraries and such are licensed under the license mentioned above, your options for licenses for your games vary depending on how you create them.
Games Based On Gluon GameProject
This type of game is a collection of assets distributed without compiling. They are the types of games created using Gluon Creator. Since these are entirely separate entities, and in licensing terms akin to a word processor document, or a movie file, the license options available for this type of game are as wide as for those:
You can choose any license you wish.
Games Distributed Through The Gluon Distribution System
This is our recommended method of game creation and distribution. This type of game is the same as above, except for an important difference: They are furthermore uploaded to the Gluon distribution system, either manually or through the Publish functionality in Gluon Creator. These games are available to all users of the various Gluon Player applications.
For this type of game, you are free to choose any OSI approved license, however we strongly encourage the use of one of the Creative Commons licenses. Please use the Creative Commons license picker to choose the license most appropriate for you: http://creativecommons.org/choose/
Other Games
Other games are those using the libraries directly - an example of this is the Gluon team's own Blok game. These games can be licensed with any LGPLv2+ compatible license.