Graybox is a modern hammer-like level editor built for Fragsurf & AIRACCEL.
Additionally, it is a minimal game engine built mostly for testing and internal purposes. Graybox.Bunnyhop is a game project with example usage.
Yes, but it's not user-friendly yet. The format is simple and easy, but there is no documentation or way of describing your game's entities. Currently, it's a static file created for Fragsurf, i.e. Graybox.Bunnyhop/Assets/Entities/Deathmatch.json
I won't provide direct support as my time is limited. Documentation will eventually be created to explain everything.
The roadmap will be posted later.
Graybox is a fork of CBRE-EX, a fork of CBRE, a fork of Sledge. It's been rewritten from the ground up, and it's very early in development. Many things will change, and many things aren't as good as they could be.