I've been playing with Miranda a little bit since seeing this yesterday, and man, I gotta say, the quality of the REPL environment and documentation is amazing.
Everything is laid out plainly, and you can learn how to work with the language in a matter of minutes.
Even the readme was one of the best I've ever encountered. It makes no undue assumptions and leaves no work up to the reader. It even notes that one may need to make certain edits to the Makefile on certain systems and, if needed, how and where one should do so (I've had to make several other programs in the past that require more tweaking and don't document the possibility or guide the user at all).
The language itself seems slim and elegant so far, but, if nothing else, I'm amazed at the level of quality of the compiler documentation, the manageable size of the source, and the REPL's design--it encourages you to write entire programs from the REPL, by allowing you to direct output to a file and to invoke an editor to modify the current scripts loaded into the environment--all this without the need for special plugins on the editor side; instead of having to invoke the REPL from your editor, your REPL invokes your editor--honestly it seems like the right relationship and now I'm fairly confused why other REPL focused languages don't commonly support this.
Everything comes bundled too--you don't need to go through some gitbook based tutorial docs in your browser to get up to speed--it's all available right from the system itself.
A lot of contemporary programming languages I've used don't have nearly as good of an onboarding experience. It makes me wonder to what extent this is just a rare case of quality work by great programmers and to what extent its symptomatic of what one can deliver with licensing and funding, as opposed to purely open-source contributions largely driven by community interest.