jsHexen2 (Hexen II)

... a redesigned jsH2 engine with external texture support for almost any object (tga, jpg, png, pcx formats, and for version 1.21+ - dds), Lit files for colored lighting, music in mp3 and ogg formats, addition of light effects, bloom, interpolation of object movement, chrome effects, etc.

I am currently in the middle of a play through of Hexen II, using this source port. It is a bit hit and miss for me, and definitely requires some settings tweaking.

For instance, the bloom and colored lighting are waaaay too heavy handed out of the box. Also, while the new HD environment textures are pretty good, I found the new weapon textures and models strayed too far from the source material for my tastes, so I turned those off.

Once you get the engine dialed in it is a really cool, new way to relive Hexen II.