Zandronum

Check here to get a version much more appropriate for usage in your own projects (probably won't break with renderer updates and doesn't replace brightmaps)
For a while now, GZDoom has been the only ZDoom-derived port to get any sort of normal mapping. But that's no more

DOWNLOAD (for Doom 1)

Here's the shader + a bunch of normal maps already done for The Ultimate Doom!
The normal mapping is completely based around dynamic lights, so it works very similarly to GZDoom.

If you think the effects are a little too subtle, you can go into Options > Display Options > OpenGL options > Dynamic Lights and increase the light size there.

Spoiler: Screenshots (Open)

Beautiful.

The last screenshot made me think of Doom3.

Brought this up to date with the grayscale bump map shader. Now supports walls too, and it should run quite a bit faster. Plus all the settings are available in func_brightmap.fp as with gs_bump.fp.