Earlier quoted context omitted.
All those you mention do have licenses. OpenEXR - https://github.com/openexr/openexr/blob/develop/OpenEXR/LICE... Ptex - http://ptex.us/documentation.html Partio - https://github.com/wdas/partio/blob/master/src/doc/license.t...
Cool, I'm glad, but still always be careful. Meanwhile, I don't really have access to a lawyer and I'm curious: 1. Should I trust a license which is not distributed with the source code (i.e. on the hopefully official website)? 2. Should I trust a license which is in a sub-directory? My initial assumption is that, only that sub-directory is licensed.
Probably you'd be able to find legal precedents for both arguments. Still, I agree with you that it's good to pay attention and understand the licenses (or get legal councel if you don't) if you're planning on doing anythnig with these projects (and others too).