There is GNU Smalltalk, but I don't think it has a big community at the moment. What you are describing, though, is conceptually easy enough to implement: mode

There is GNU Smalltalk, but I don't think it has a big community at the moment. What you are describing, though, is conceptually easy enough to implement: modern Smalltalks (Squeak, Pharo, and friends) all have robust interfaces to Unix and stdin/stdout. You could easily create a repl. It's also easy to make TCP, HTTP, or WebSocket servers, so you can create interaction that way as well. And of course there is Seaside, which has some tools already for interacting with a Smalltalk image through the browser. Another approach is Amber Smalltalk, which is a web-based Smalltalk for frontend development (amber-lang.net)