From the website:
"SpotLook is a graphical interface to Mac OS X Leopard's Spotlight desktop search engine. It features tracks, which are timelines showing results according to their date. Tracks can created, edited and customized include a search scope and attributes to search for. Found items can be viewed with Quick Look or revealed in the Finder. This is an 2500 Objective-C lines open-source project; your contributions are welcome. You also discuss SpotLook, send feedback and ideas on the Discussion page."