I was watching some videos for the upcoming game "overgrowth" when i came across a video where they demo their tools that they use to make their game content.
Map editor:
I'm really a blown away about all the technology that's going into this game, their tools feature particle editors, decal editors, animation editor, a map editor, and even more. Of course the map editor isn't as complex as Hammer, but it is significant, kind of like a beefed up version of halo's forge editor, the ability to resize, retexture, and position blocks in real time with lighting is really outstanding i think. Overgrowth will apparently be open to modders right out of the gate, and you can even get your hands on all of these tools if you have the game preordered.
All this from an indie game company? It just seems unheard of.