Interesting:

• Plone.org pumps out about 4m hits a month
• Zope.org (which must do about 1/2 as much again) has just been relaunched based on Plone

So to everyone who questioned whether Plone could handle any amount of traffic: Bite my shiny metal ass.

Here's the detail of the setup each uses:

• Zope.org architecture
  
• Plone.org setup

  plone.org is a powered by a Dual 2 GHz XEON with 1GB of RAM. It is running use ZODB3.1 ZEO server and has 2 ZEO Clients running. Apache is run in a mod_proxy configuration where it caches static content from Zope. Apache proxies requests to a POUND daemon which load balances (round robin) between the two ZEO clients. A very simple and effective combination.