While I'm not a user of this editor, this seems like great news.

4coder receives significant attention via the Casey Muratori's video streams like Handmade Hero, and opening it up is sure to produce some positive growth for the development/community side of the project.

The combination of popular development livestreams and FOSS tooling utilized in those livestreams seems like it could be an important part of making FOSS development more sustainable without involving big corporate sponsors.