Turck MMCache (GPL) |00AA00|Implements many features beyond opcode caching.| |FF0000|Development halted.| APC (PHP) |00AA00|Slow, but steady progress.| |FF0000|Weak optimizer.| ionCube PHP Accelerator |FF0000|It works, but no new development in past year.| |00AA00|Free|, but |FF0000|closed source|. Zend Cache (Proprietary) |00AA00|Implements many features beyond opcode caching.| |FF0000|$$$|