GWT Smalltalk (GST) is an implementation of the Smalltalk language which runs in web browsers.
It is built using the Google Web Toolkit (GWT) and is deployed on the Google Application Engine (GAE).
GST is designed to be used as development environment for the creation and maintenance of web-application clients. The GST server-side component supports GAE “Big Table” database access, instant messaging through XMPP, and the current release of the Google Wave API.
Classes and method lookup are implemented similarly to Smalltalk-80 – class inheritance, instance variables, “self” and “super” are all explicitly supported.
GST is undergoing development and there are still many omissions and errors in the code.
You are welcome to take a look here.