   Question on SlimDX license
  [color="#4E4E4E"][font="Helvetica, Arial, sans-serif"]* Share Alike - If you alter, transform, or build upon this work, you may distributethe resulting work only under the same, similar or a compatible license.Does this part means that SlimDX could only be used for free to develop free and open source apps?[/font][color="#4E4E4E"][font="Helvetica, Arial, sans-serif"] And if we are planning to use it in a commercial product - then we should buy it or consider to use something else, like XNA or Tao?[/font][color="#4E4E4E"][font="Helvetica, Arial, sans-serif"] Thank you for the answers![/font]   
  No, you can use it just fine in commercial products; a few commercial games use it for things such as pre-game setup and splash screens. If you do use it however the SlimDX team do like to know about it but you don't have to tell them The clause there is about the source code; if you take the source and build upon it you can only redist that source under a similar licences... thus, if I'm understanding it right, you could take the code, make a change and then re-dist as something like GPL. However you don't have to redist the code if you change it based on that snippet of the licence.In short; go for it, SlimDX is awesome ;  That snippet you have there isn't from SlimDX's code license, it's the Creative Commons Attribution-Share Alike 3.0 license. As mentioned on their homepage this license is for "All other parts of SlimDX, including all artwork, logos, audio, etc...". SlimDX's source code and binaries are licensed under the MIT/X11 license. So if you change or use content from the SlimDX Sample projects, that stuff falls under the Attribution-Share Alike license, but using the library binaries falls under the MIT license.And yes, it is perfectly legit to use it for commercial applications and other closed sourced application, as Phantom mentioned.   