It is now called Sherlock and can dig up information using multiple search engines across the entire Web. Information is ranked by relevance and with summaries.
Sherlock uses plug-ins that can be downloaded from individual Web sites.
Of course dealing with all these plug-ins can be a hassle so developers have come up with solutions. It also allows you to group plug-ins into sets so you can manage your specific search. Doyle just asks you for a URL, and some basic information. Lestrade is the successor to LazySearch. It is a fast and flexible plug-in architecture lets you customize Lestrade to suit your individual needs.