PyPy, the Python implementation written in Python, was mentioned here a couple of times in the past. After it was mentioned in a recent LtU discussion, I took another look, and boy did they make a lot of progress when I wasn't looking. PyPy can even compile itself now... You should check it out again if you are interested in this sort of thing.

There's even an introduction to the techniques used by PyPy, including a nice (but very high level) overview of abstract interpretation.

Dan Ingalls 7 Smalltalk implementations video

Stanford University, Oct 24, 2005

The nice thing about a language that takes hold is that you can work with it again and again. In 30 years we have built Smalltalk systems with quite different constraints. This talk will examine a few of these, and show how tricks of the trade can be applied to enhance one aspect or another and, frequently, to make real progress.

Blockquote color

I don't like how the blockquote color is in blue, the same color as hyperlinks. Why not keep it black? They already stand out by being indented, having the bar in front, and being in italics!