SmallJ is a simple Smalltalk virtual machine written in Java.
It was originally created as SmallWorld by Timothy Budd,
this version being an extensive rewrite of Eric Sharff's update.
The goal of SmallJ is to promote the Smalltalk programming language,
which is still the most elegant object-oriented language out there. :-)
And possibly to make it into a useful system for some production / scripting work.
The full Smalltalk + Java source can found on GitHub: