CacheFu speeds up Plone dramatically by integrating with caching proxies like Squid and Varnish, as well as in-memory/browser cache settings. It is bundled with plone 2.5.5, but the related Products are installed in a subdir that is not taken into account by the plone product installer. My simple patch (attached) take care of that. Care to review? Reproducible: Always
Created attachment 147428 [details, diff] plone-2.5.5-cachefu.patch