The Indie tower defense action-RPG game Dungeon Defenders has added support for Steam Workshop, allowing players to easily discover and download custom mods and maps made by the community. These new maps and mods can be used to play online or locally, and work across both PC and Mac using SteamPlay. Content is authored using the Dungeon Defenders Development Kit, based on Unreal Engine 3, and can contain customized artwork, enemies, loot items, and game code. So intrepid map designers and programmers take heart, you now have a built-in Steam audience for your original creative work.
If you own Dungeon Defenders, you'll find the Development Kit in the 'tools' section of your Steam library.