tldr I plan to make the singleplayer at least source available, but keep all parts related to multiplayer/persistence/hosting (anything that requires a server) closed for a few practical reasons:
1. Cheating: There has to be some security by obscurity because in Easel, multiplayer and persistence are actually client authoritative. Why client authoritative? We don't simulate on the server to keep costs down. Why keep server costs down? Easel will never run ads because it is aimed at teenagers/children and we want to be able to vet all content shown on Easel. Without ads, combined with the fact that we want Easel to be free for teenagers, the budget is extremely tight. I would rather die than get VC funding because they would force Easel to put profit before principles, so we have to keep the costs low.
2. Development speed: Easel has changed a lot over the past 3 years, and been constantly refactored over and over again. If you look at Easel now, you might think "I could make that" but when I made it, I didn't have any reference points, so I had to iterate and iterate on a lot of things from first principles and take a lot of wrong turns. My GitHub history shows me adding about 2 million lines of code even though the project is about 150000 lines, which shows how much it has been written and re-written. Anyone who tried to contribute would just get in the way at this point. I want to spend my days coding rather than arguing with people on GitHub.
3. Survival: I don't want someone else to take all the code to make a competing platform which does not have the same principles (like putting profit ahead of child safety and showing ads). My dream is for Easel to be a place where most players are makers, like Scratch, except with more actual real games on it because the engine has built-in game features like a physics engine, particle systems and multiplayer. Like Roblox except actually beginner-friendly coding. I have a vision quest and I want Easel to fund Easel so I can make Easel.
I am looking to open source Easel but only in a way which solves the above 3 problems. The way that I have come up with is that open sourcing the singleplayer parts is the best compromise between everything. It just requires stopping development to splitting it all out, and having all the code split out will mean development would be slower, and I am prioritising development speed at the moment. The engine is not complete enough yet and missing a bunch of key features which would stop numerous games from being made. So maybe in a couple of years I will have the bandwidth to look into this. But I actually want to open source Easel, but I just need those problems solved.