Jacob Santos is back again today with this new blog post - his look at the world of PHP compilers and some of his theories (and rants) on the subject.
I know very little of compiler and interpreter theory and have never (yet) created a working implementation of a compiler or interpreter. What you're about to read or (most likely) skip over is a Head-in-Ass post and feel free to flame me on parts where I'm wrong, which will be most places. Do realize that this is one end user's opinion of the matter and any perceived insult upon any author(s) is not intended and please do not take it as such.
Jacob talks about run-time classes, class optimization, what he "really wants" out of a compiler, namespace functionality, a "phpc" extension, and his opinions on the Zend Engine, other web technologies, and the future of PHP.