Dear Poly/ML enthusiasts,
quite often the best-known system in a certain category is not really the best. The website https://alternativeto.net occasionally helps to turn perception into reality, by choosing a proper alternative.
I have already created entries for some implementations of Standard ML on this site, including https://alternativeto.net/software/poly-ml
Maybe some people on this list want to add some more, add likes, comments etc. as a proof that Poly/ML is presently the center of active Standard ML development.
Makarius