Thunderstone is a truly pioneer in the enterprise search field, founded in the 1980′s. Appears to be very accurate, and is one of two that is able to give a meaningful answer to the “to be or not to be” query. Available as bout a virtual appliance (to be run on VMware, Xen, Virtualbox etc) and as a hardware appliance.
You can try a demo of Constellio online here.
Search result page
Thunderstone has a quite basic but classic search result page.
Hits has a title or the file name at the top, three lines of hillited text extract and then the url at the bottom There is also some meta info and links to find similar pages, match info and show what folder the page was found in.