Per-Pixel Ligthing

I have implemented per pixel lighting in tangent space, it was implemeted as a small test project in my engine so I still need to integrate it with the rest of the engine. The plane visible in the screenshot is made up off just two triangles, and all the lighting details are calculated in the shaders. It calculates diffuse light using standard lambertian shading and does phong shading too. The wireframe sphere hovering above the plane is the light. The whole thing is written in ARB_fragment_program and ARB_vertex_program shaders.