POMF is a set of open, unencumbered Minecraft mappings, free for everyone to use under the Creative Commons Zero license. The intention is to let everyone mod Minecraft freely and openly, while also being able to innovate and process the mappings as they see fit.
The current version targets Minecraft version 16w32b.
Download Enigma from here (source). Use the "-all" JAR.
Please remember that copying and pasting mappings from alternate projects under more restrictive licenses (such as MCP) is completely forbidden. It is also good to consult name changes with other people via pull requests.
WIP mapping guidelines are available here. Feel free to contribute. It is also good to discuss naming schemes with the developers on IRC or inside a pull request.