[stchang]

FWIW, the phase system that is the main topic of the article was created for Racket [1], though some Scheme macro systems have since adopted this Racket innovation.

[1]: https://www.cs.utah.edu/plt/publications/macromod.pdf

[brudgers]

Racket also has the concept of a documentation phase. Matthew Flatt wished it into existence when creating Scribble.

[dleslie]

Chibi[0] supports Scribble. :)

0: http://synthcode.com/scheme/chibi/lib/chibi/scribble.html

[samth]

I think it (like Guile) just supports the reader syntax, rather than the semantics (which is heavily based on Racket's macro system).