Smalltalk Virtual Machine

The SmalltalkVirtualMachine is a VirtualMachine that allows a Smalltalk image to run on an underlying platform. The SmalltalkVirtualMachine executes compiled methods whose code is expressed as ByteCode sequences. It includes a process model, stack-frames, closures (sort of), and a variety of debugging hooks.

The BlueBook described an early SmalltalkVirtualMachine, no corresponding VirtualMachine was ever actually built. The early SmalltalkVirtualMachines, built by Xerox, varied from the BlueBook in significant ways.

Later versions diverged even more dramatically, including the "HPS" implementation that supported JustInTimeCompilation, various compiler optimizations, and several varieties of bit-mapped graphics magic.
