According to https://openmw.org/faq/#legal_stuff
The wiki link though says nothing about the shaders and the shader files themselves contain no license header.All fonts, shaders and other assets shipped with OpenMW are licensed under separate terms. Details can be found in the Readme file or in the Wiki.
Background: I would like to use some of the shader code in a LGPL-licensed project of mine: https://www.sas1946.com/main/index.php/ ... 926.0.html - a graphics extender for Il-2 Sturmovik.