Re:Yafray (Score 1)

Just to make sure those not familiar with the POV-Ray license don't misunderstand this - POV-Ray can of course be used to create images for any commercial purpose and the source code is available for studying and creating modified versions as well. But you have to obtain permission from the authors for commercial bundling of POV-Ray. If you want to study the license conditions see the

• end-user license
• distribution license
• source license

That said everyone is of course free not to use POV-Ray for whatever reason...