Original Mode From Xavier Decoret is here:
http://artis.inrialpes.fr/~Xavier.Decoret/resources/glsl-mode
With modifications for up to GLSL 4.3:
https://raw.github.com/jimhourihan/glsl-mode/master/glsl-mode.el
repo with modifications is here: https://github.com/jimhourihan/glsl-mode