Enfold Enterprise Proxy can greatly speeds up your Plone site by caching pages inside IIS. Usually, EEP will automatically notice when your Plone site has changed, so it is always up to date.
If you crave the ultimate in speed, you can set EEP to not check your Plone site so often. That's where "purging" comes in -- a remote command to tell EEP to drop its cached versions of a page, or the whole site, and fetch the latest stuff. CMFSquidTool allows you to send such commands right from your Plone site.
It's called CMFSquidTool because this is slight modification of an existing open source tool for Squid-cache. Our version should also work with Squid too.
Available versions of the software can be found in the downloads area.