9rules has developed a custom-built search engine for its members' content. I've always admired 9rules' philosophy (note: R/WW used to be a member), because they're all about original content and design. Now they're trying to make it easier for others to discover all that great content, with a search interface that only searches content in the 9rules community. Mike Rundle explains:Blog network
"The first year or so of 9rules existence was about grouping great content together, and if I had to categorize the next year I’d say our goal is to now distribute this content in interesting and meaningful ways and 9rules Search is the start of this next big push."
Mike has a full list of the features in his post, but the ones I liked the best are integrated communities ("go directly to the Community associated with that particular entry if you want to read more on that topic") and some nifty Ajax work to integrate Flickr and YouTube. Features I'd like to see in future include RSS feeds for topics (e.g. I may want to subscribe to 9rules members on 'web design') and perhaps the good old tag cloud could be employed.
Custom or social search is a product category that I'm tracking, because it brings the 'social web' element to probably the most important of all Web interfaces: the search box. Eurekster is a great example of an up-and-coming social search company - they believe that niche and DIY search engines are the way of the future. I'll be exploring more of this in the near future. In the meantime check out Ebrahim Ezzy's two-part series here on R/WW in July, Search 2.0 vs Traditional Search (and Part 2). And congrats to 9rules for bringing social search to their community!