SearchSpring - SearchSpring is an eCommerce site search tool.
Xobni - Xobni provides effortless email and address book management and search for Microsoft Outlook and BlackBerry. Put a face to every name. Lightning fast Outlook Search.
SearchBlox - SearchBlox is an out-of-the-box Enterprise Search Solution built on top of Apache Lucene/Solr.
Live Inbox - Live Inbox is a Microsoft Outlook plugin that helps you organize your email and search your inbox.
Hulbee Enterprise Search - Hulbee Enterprise Search is another powerful site search solution that intelligently retrieves information and documents regardless of their source or location.
X1 Search - X1's Lightning-Fast Search Software. Premium Alternative to Windows Desktop and Outlook Search.