I tried to get it working in SDLMame/SDLMess. There are probably bugs (for sure there are because I don't think it works with the NTSC shader...), but it works pretty well any way. They may be fundamental errors because I'm not a programmer, don't really know how the GLSL system in MAME/MESS works, and I am easily confused by texture coordinates.
The shader's best features, IMO, are an aperture pattern that looks better than others I've seen and a sharpness parameter that is easily tweaked to your liking.
It also supports tweakable screen curvature, scanline darkness, and aperture pattern brightness.
I added a few possibly stupid things to the original shader: scanline varies with pixel intensity, contrast/gamma boost to help offset the natural image darkening of the aperture effect, a modification to the way sharpness works so that it is a little more consistent between drivers, and YUV saturation and tint settings.
If you use SDLMAME or SDLMESS with GLSL shaders, then you might want to check it out.
Tried to get Timothy Lottes' CRT Shader working with SDLMAME.