I wanted to try out Maxine on my MacBook Pro running Mac OS X 10.5.8. I followed these steps to try it out:
hg clone https://kenai.com/hg/maxine~maxine maxine
export JUNIT4_CP=<full-path-of junit-4.4.jar>
Wow! Maxine VM printed "Hello World!". Now, it is time to explore Maxine's inspector and other cool stuff ...