Been making my own procedural terrain - about the third try, but first real terrain generator I've made that works well. I've been the Unity3D game engine for this stuff.
Make 1 4channel perlin that stores various data (rivers, mountains, terrain type) while another 4channel is used for actual terrain height.
It's going to be either 8x8km, or 16x16km
I love doing things procedurally - I hope to have entire towns (and individual buildings) procedurally generated.
Honestly, please do. I want to see how low I can go!!
Ignore that error message too. Just ignore it and keep going to give me -rep.