I use ports to write to the filesystem. There is a small amount of JS that initializes Elm, which runs in Node and has the ability to write to the filesystem.

I use ports to write to the filesystem. There is a small amount of JS that initializes Elm, which runs in Node and has the ability to write to the filesystem. Of course if you'll be running elm-in-elm in the browser, you won't be able to do that. But there are more interesting things to do with a compiler in the browser :)