This project was not only heavily inspired by someone else's, but it's more or less a complete recreation. When I found Florian Boesch's Minecraft Like Rendering Experiments in OpenGL 4, I was rather inspired by how simple it was, while still demonstrating a number of techniques I was particularly interested in. So I decided to brush up on my OpenGL skills and learn those techniques by reproducing his project myself, without ever referring to his source code. Rather than Python and C, I wrote mine in C# using OpenTK.
If you haven't yet, go to his web site, watch his video, and read his writeup. His video is better, and there's no sense in me rewriting the very writeup I learned from. It's a great introduction to using noise, spherical harmonic lighting, ambient occlusion, gamma correction, normal mapping, specular mapping, radiance, and fog.