If you own delightful dungeon-crawler Legend of Grimrock on Steam, you can get cracking on making your own hellish holes as developer Almost Human Games today released a beta version of the editor. Initially available only on Steam (with Steam Workshop support), it lets you make everything from your own levels to, ah, an angry cow on wheels.
The map editor seems a pleasingly simple affair, letting you draw out spaces then allowing you to quickly pop into your level to check it out. It also supports making new items and monsters, LUA scripting, replacing cinematics, and importing custom textures, sound and music. You can make something rather new and exciting, in short.
The beta version is only available on Steam, Almost Human explains, because it's quick and easy to roll out frequent updates. It'll be available for people who don't own Legend of Grimrock on Steam once it's finished, though, and Grimrock Nexus has been set up for the poor souls who'll also be deprived of the Steam Workshop.
To download the beta editor and start making the cow level of your dreams, right-click on LoG in your Steam Library and go into the Properties, then opt into the beta through the Betas tab.
Here's a little red-hot editor action: