LIPS: Scheme based powerful lisp interpreter in JavaScript for browsers and Node. Maintained by @jcubic Aspiring R7RS Scheme.
Check Scheme Bookmark REPL.
A new beta version of LIPS Scheme got released.
This is a huge version. The evaluator was rewritten, and now it supports continuations and TCO (tail call optimization).
Chibi R7RS test status so far.
Not bad; the numerical syntax requires parser changes.
Also, I liked that 1e10 was converted to BigInteger. But this can be done with #e1e10.
I'm thinking of obeying the spec and removing that feature.