Zambeel is an e-mail based archiving system that was designed to address the needs of people who move around frequently, but need to keep their files in one place. Files that need to be stored for future reference can be emailed to the system as an attachment. It then stores them as part of your personal archive, which can be searched and accessed later.
Red-Piranha is a search system that can actually learn what you are looking for. It can be used as a Web page, command line, or XML-WebService, so it will work with most languages, including Java, Perl, C#/.NET, and PHP. It includes learning abilities for the Desktop/Internet search functionality. All feedback from the user is stored in (editable) XML and RDF, and is used by the system to improve the quality of searches.