Comment by wirybeige

The post links to this: https://github.com/MCRcortex/nvidium

nvidium is using GL_NV_mesh_shader which is only available for nVIDIA cards. This mod is the only game/mod I know of that uses mesh shaders & is OpenGL. & so the new gl extension will let users of other vendors use the mod if it gets updated to use the new extension.