Ferret CMS is a Content Management System based on Zope. It is focused on easy administration and fast deployment of a web site. It has a workflow mechanism with roles that can be assigned to backend users.
Omseek has been renamed to Xapian. Xapian is a Search Engine Library, written in C++ with bindings for Perl, Python, PHP, Java, Tcl, C# and Ruby. It allows you to easily add advanced indexing and search facilities to your applications. See xapian.org
Cheshire3 is a fast Z39.50, SRW, XML search engine, written in Python for extensability and using C libraries for speed. Next generation of the Cheshire system (http://cheshire.berkeley.edu) and designed around a distributable, object oriented model.
Zope is an open source application server specializing in content management, intranets, and custom web applications. Zope is written in Python and has a large, global community of developers and companies.