HotSpot is a pretty sweet piece of technology, with an illustrious lineage back to Ungar and Smith's beautiful Self language[1] and the Strongtalk[2] Smalltalk VM implementation.

If this kind of "black magic" excites you, I highly recommend digging into both of these decades-old projects.

Terrific link, luu.

[1] http://www.cs.ucsb.edu/~urs/oocsb/self/papers/papers.html

[2] http://strongtalk.org/history.html