CryDev has released their CryENGINE 3 SDK to the public with various license models ranging from free with limited commercial use to also 2 commercial license models. For those who might not know it, it is an extremely well developed and powerful game engine which is used for the popular Crysis game series.
This SDK besides the CryENGINES has enough tools to also fully develop new games from scratch - not just mods.
Read more in the following:
Anyone can now download a full version of the best All-In-One Game Development Engine, for free and use it without charge for non-commercial game development. Try out the fastest toolset for creating game worlds and use the power of CryENGINE 3 in your own games
CryENGINE Free Use
You can use CryENGINE 3 for free in educational facilities, even if you are charging tuition. We have always offered our engine for free to educators, but now individual students can also freely download the engine and use if to learn about real-time 3D development.
CryENGINE 3 is also free for non-commercial use; if you are distributing your game or application for free (and not charging for your work in producing it, whether directly or indirectly), no additional license is required.
CryENGINE 3 Independent Developers Platform
We want you to make games with CryENGINE 3 that people will want to play. We hope that your work will lead to a product you can commercialise. If this is the case, before you can sell your work or your game, you must seek a development license for CryENGINE 3.
CryENGINE 3 for Independent Studios, Free To Play Games or Downloadable Games
Crytek has attractive options for smaller games built with CryENGINE 3, with shorter development timescales. If you want to move your game onto platforms other than PC, or you need access to CryENGINE 3 source code, please contact Crytek to find out more about our licensing for Independent Studios.
For those developers that are looking to make the step in to commercial gaming, Crytek offer a royalty-only license model for any games created with their SDK. Where Crytek will only ask for 20% of the revenues from the commercial launch of the developers game.
There seems to be a little bit confusion about the license models for the commercial application - but I assume time will clarify this.