Shaders modifies the EntityRenderer, Tessellator, RenderBlocks, RenderGlobal, RenderLiving, and RenderEngine classes. Usually, if you install this mod after other mods it will work fine. However, there are a few exceptions.
Optimine does not work and will likely never work with Shaders.
The latest release attempts to detect Wild Grass and install correctly with full functionality but some bugs have been reported. Wild Grass will work if you install it after Shaders. However, doing this will prevent any sort of bump mapping from functioning correctly.
Extreme Increased View Distance
GLSL Completly overwrites the files used by this mod. n.class and px.class.
Optifog for 1.5_01 (B Version) does not work with Shaders due to both modifying rendering methods.