On PHPEverywhere this morning, there's a new posting that talks about an article from the latest PHP Magazine about the PHP Compiler Cache Internals.

From this post: If you're familiar with the English expression, don't throw the baby out with the bath water, then you will be amused to learn that that's exactly how the Zend Engine (PHP's compiler) works. It will compile the PHP into opcodes for a page request, and throw the opcodes away immediately after the code completes. [...] This omission of the Zend Engine stimulated interest in several open source developers to create their own opcode caches. APC is one of the earliest open source opcode caches.

It goes on to talk more about benchmarks of the PHP opcodes and their caches, and the discovery that it's not the opcodes themselves that are copied, but the structure containing them and pointers back to the originals. Of course, the door is wide open for other compilers (like APC) and the PHP world is more than ready to get testing...