Cool! Went to check it out today and it was quite an adventure getting out of spawn. There was lava everywhere.
WebSandboxMC is looking better and better all the time, but there was land outside of the limited web-based area, looked like the example terrain from here.
ThinkMap did not render anything, due to some errors:
uncaught exception: Class$S368: 0:2(12): warning: extension 'GL_ARB_gpu_shader5' unsupported in fragment shader
0:19(35): error: sampler arrays indexed with non-constant expressions are forbidden in GLSL 1.30 and later
Dynmap looked good, but it seemed like the edges of the map were bugged. I don’t remember what map edges are supposed to look like though, so it might be fine.