RPM search engine and download site - www.rpmwiki.com
Xapian is a Search Engine Library, written in C++ with bindings for Perl, Python, PHP, Java, Tcl, C# and Ruby. Xapian allows you to easily add advanced indexing and search facilities to your applications. See www.xapian.org for more information.
Search engine with web-interface,which can be installed on Linux and Windows machines, and disturbed across LAN to decrease scan time.