Terrain Generation using c++

I know there are quite a few questions on this subject matter but none have really been answered/ are what I'm looking for.

I'm currently looking for ideas on what to for my final year project at uni. I've looked at terrain generation and it's an area that interests me a lot however I have no idea at all where to start. Having read through the relevant sections of Programming Gems v1, I slightly understand midpoint displacement and the Diamond Square algorithm however I don't understand what programs would let me create 2d/3D terrain or how/ where to start.