SableVM is a bytecode interpreter. It's goals are to be reasonably small,
efficient, and fast, as well as providing a well-designed platform for
doing research into different algorithms for bytecode interpretation,
garbage collection, memory management, etc.
SableVM uses a modified version of the GNU Classpath Java classes;
these classes are installed by the "sablepath" port.
WWW: http://www.sablevm.org/