Via James Robertson, Pier has been ported to Cincom Smalltalk. What's that mean?
And Cincom Smalltalk may be the best OO dynamic language system, probably the best such commercial system, and has all the openness that Smalltalk systems have had going back to the early 1980s. In fact CST's lineage goes all the way back. (Why would you use Ruby when you could use Smalltalk???)
Cincom has or will soon have support for Seaside. Try out Pier. It's cool.