Mecha is a little solid modeling language intended for machine design. Mecha has two layers: a pure functional layer for defining solids (aka. parts), and a monadic layer for arranging parts into assemblies. Solids (parts) are built using set operations on solid primitives. A solid primitives is simply a predicate that says whether a point in space is inside the solid: data Solid = Solid (Vector -> Bool) Mesh generation is performed by adaptive marching cubes. It's slow, especially if you don't have graphics hardware. And solids with hard edges don't render very clean. But the basics work. Here's a simple example: example :: IO () example = view design design :: Asm () design = do a <- part 1 0.06 8 $ difference sphereCube cyl3 b <- part 1 0.08 8 $ sphereCube c <- part 1.5 0.08 8 $ cyl3 color (0, 0, 0.8) $ place a move (-4, 0, 0) $ color (0.8, 0, 0) $ place b move ( 0, 4, 0) $ color (0, 0.8, 0) $ place c sphereCube = intersection sphere $ scaleXYZ 0.75 cube cyl = scale (0.5, 0.5, 1.2) $ cylinder cyl3 = unions [cyl, rotateX (pi / 2) cyl, rotateY (pi / 2) cyl] Screenshot: http://tomahawkins.org/ Enjoy!