FreeGameDev

Platinum Arts Sandbox Free 3D Game Maker is an open source game design program for kids and adults. Through the ingame and cooperative editing and focus on ease of use the program is easy enough for kids to use but powerful enough for full game projects. Sandbox includes Save The Princess Gameplay, an RPG Maker, a Sidescoller maker, a Movie Maker aka Machinima, Save The Banana Base Capture, and more! Sandbox is already being used in many schools and colleges throughout the world and included in game design contests.

Looks great!

Just thought I'd point out that this engine is not news, it's based on Cube2, and it has (or had) license terms that don't respect the Four Freedoms. So yeah...

Deleted.

No, Sauerbraten had/has assets under NC. Cube2 is just the engine. Platinum Arts Sandbox is or was nonfree in the strictest sense, but Cube2 (the original engine) is zlib licensed and nothing more. The Bananabread project is Cube2 with FLOSS assets and Emscripten support, and it's probably the cleanest way to get the Cube2 engine.

Also I thought I should mention that Wouter probably didn't make this differentiation initially, the community did. Projects like Bananabread strip the nonfree assets away from Sauerbraten to get the core they call Cube2 and build on that.