github/linguist — pull request #1073 by tajjada (2014-04-17 08:08:20+00:00)
Title: Add .vshader, .fshader, .gshader files for GLSL.

I have seen .vshader and .fshader extensions being used for GLSL shaders in many places. I use them myself.

Although I have never seen .gshader, I added it too. It is logical by the pattern.