I was discussing to implement some web projects based on either Zope or the Twisted framework. The latest version of Zope 3 now replaces the internal ZServer with the Twisted framework. Maybe this distinction becomes more or less obsolete:
The ZServer has been replaced with the Twisted server. The Twisted server supports all that the ZServer supporting has well has HTTP over SSL natively and SFTP (disabled for now because of error handling problems). Also in the future it brings a better chance of other non-HTTP related protocols from being implemented for Zope3, like SMTP-in and IMAP.