It’s true, Scuttle.org is an open source social bookmarking platform. A variety of different social bookmarking services seem to use it, but none I had ever heard of before looking. http://sourceforge.net/projects/scuttle/ is where you can download the code. Is there an implementation out there where you could, say, both search in and by found in both Scuttle and Del.icio.us at the same time? Wouldn’t that be nice.