OpenGLSL is a project mainly written in Vim Script, it's free.
OpenGL Shading Language syntax script
This is a mirror of http://www.vim.org/scripts/script.php?script_id=1220
A syntax script for builtin functions, uniform variables, constants and types for the OpenGL Shading Language V1.1 (http://www.opengl.org/documentation/oglsl.html)