Folk from the now defunct Ion Storm have released an editor for Thief:
Deadly Shadows. The editor allows you to create and tweak content in the game, and comes with some tutorial maps, and
what seems to be a boatload of instructions.
From the instructions, the editor also seems to work for Deus Ex: Invisible War. So two for the price of one!
Score!
Get editing! Let the Ion name live on.
