Apache Lucene site -- powered by Google
What's wrong with this picture? (Hint: Apache Lucene is an open-source search framework...)
Note: After seeing this blog, Andreas Hartmann (of the Apache Lenya team) wrote to us to explain that "The Lucene team uses Google to provide search functionality for their website because of infrastructure restrictions of the Apache Software Foundation. Only static HTML files are allowed on the webserver. It is not possible to deploy Java-based web applications."