A PHP VM implementation written in PHP.
This is a basic VM implemented in PHP using the AST generating parser developed by @nikic
To see what's supported so far, check out the opcodes.
Right now, functions (definitions and calls) are supported, if statements (with basic boolean operations), if statements, as are variables and some basic variable operations...
To see the current state of the implementation versus the Core Language Test Suite, check out the test results file.