Doom 2016 Alpha contains id Studio
It was discovered by an anonymous user that the Doom 2016 multiplayer alpha contained a launchable version of id Studio. Using a DLL that hooks into the binary they were able to launch it. However, many required files for it to function properly were not bundled along with the game. Older files from the id Studio for Rage release were used to get it working, but those are out of date and seem to cause problems.
Within the .exe there appears to be a lot of id's tool code, including code for AAS compiling, "CPU VMTR" generation, and other stuff [list the other stuff in the exe here]. This binary is the key to one day having custom Doom 2016 maps.
Within the id Studio build not much is functional. The particle editor works sometimes.
Note: This page was originally written by Chrispy. It was recovered from the now-deleted idTech 7 wiki, and copied here for preservation. This information is incomplete and needs further details to expand upon it.