Awhile ago I made a thing that I didn't talk about. In fact, lately I've been doing that a lot, so hopefully I'll get better about boasting about myself like a good blogger.
I wanted a way to download scripts in a Unity executable and run them (particularly on mobile). A working REPL would also be nice. So I started
What's important about Jint is that it's an interpreter that does not require the DLR and does not generate bytecode. This is important if you want to be able to run on targets that require Unity to AOT compile everything (like iOS). Jint isn't perfect though. It has actually recently dropped support for .NET 3.5 and does loads of other stuff Unity doesn't support. But it's pretty dang close.
So I started a fork with all these issues taken care of.
Here's a screenshot of an example REPL:
It has some pretty cool features, like a builtin require() function, much like node.js. Require will essentially load a script, execute it in a sandbox, then return the result for code sharing.
inject() is pretty cool too, because it lets you specify how to resolve objects from Unity land.
In conclusion, I'd like to thank the years of work that 40 contributors put into Jint just so I could make a poor-performing JS REPL in Unity.