[Shameless plug approaching] Or using something like CodeParadise to run Smalltalk in the browser as well as on the server.
https://github.com/ErikOnBike/CodeParadise
@Rafi Khan I'm also interested in this topic. (The start of CodeParadise was to create a development environment for kids.). My current idea (only in thought, nothing tried out yet) is to have a language like Smalltalk, but without the static class hierarchy. Somewhere between Self and Smalltalk. Allowing the addition and removal of behaviour to/from objects. Using the Smalltalk syntax. The static class hierarchy sometimes feels as a hindrance. Only if you're already comfortable with such a structure and/or can do the 'abstraction thing' you're able to create class hierarchies that actually work/are beneficial (even in the long(er) run).