This cache manager uses a dedicated perl module for Apache (it's included with this package) to cache documents on the Apache side of a Apache+Zope combo. This gives you full control over caching properties through the Zope management interface while giving you a near-static-access performance for requests to cache hits. The resulting cache is very fast and still honors authentication information, cookies and parameters to the document. It was developed to enable us to serve multimillion hit systems through Zope in a distributed fashion. Since the cache itself is just an Apache with some directories, this can be clustered and performance can be beefed up with the usual tools without worrying over Zope too much. If your system will get many hits, you might want to look into this tool.
From version 1.0.1 on you can manage your cache contents with Zope (flush the whole cache or invalidate single documents).
From version 1.0.3 on it even works ;-). You most surely want to upgrade to 1.0.3, because the former version is broken in some nice and funny ways.