Crawlzilla is a cluster-based search engine deployment tools. It helps user to build search engine in your cluster, and offers management mechanism (such as: cluster management, crawl management, index pool management...).
Open source project that offer summary and download services on this page is a project that carry out their development work on other open source development sites. Their work is linked to this page via a feature called OFI, and their work is not carried out here on OSDN site.