Unfortunately it looks like mmcache has reached the end for the latest PHP 4.
[email protected] [~/turck-mmcache-2.4.6]# service httpd start
Turck MMCache requires Zend Engine API version 20021010.
The Zend Engine API version 20050606 which is installed, is newer.
Contact Dmitry Stogov at http://turck-mmcache.sourceforge.net for a later version of Turck MMCache.
I tried e-mailing the address on their web site, but it bounced.
This is a shame... I hope the owner will make a return.