I don't think of Mudcat as a service or a resource in that way. The resource is access to a large number of people who are prepared to take the time and trouble to answer - to the best of their admittedly fallable ability - questions on folk and blues largely based on their own current experience of performing that music. That is a different sort of resource to, say, the Vance Randolph or Child books, or to archive recordings. Yes, if you are interested in academic research formal libraries are what you need and sites that make these resources available to the world via the web are fantastic. But its not the same thing as people performing today. And the Mudcat resource, in my terms, is not one that search engines like Google are terribly good at finding. But they do find it if you are interested enough. Its how I got here!