Google acquires companies all the time, little startups with a bit of helpful technology or a nice patent or a few engineers Google wants. Today's acquisition of Metaweb should not be grouped in with those relatively small other purchases: Metaweb's technology could change the way Google Search works.
Metaweb is a difficult concept to describe, although the video above does an admirable job. Essentially, it views keywords, the way we search now, as an inferior search method to what it calls "entities." Words can vary in meaning, refer to different things, have different levels of importance or relevance at different times, and often return inexact results. So Metaweb has created a constantly growing database, or directory, of 12 million "entities," which are really just persons, places, or things, and all the different ways you might refer to them. Wording isn't so important with Metaweb, it's the end meaning that matters.
Once Metaweb figures out to which entity you're referring, it can provide a set of results. It can even combine entities for more complex searches--"actresses over 40" might be one entity, "actresses living in New York City" might be another, and "actresses with a movie currently playing" might be another. Instead of searching through that jumble of keywords, Metaweb would just connect you to those three entities, and file down your results.
You can see why this would be extremely valuable to Google. In a blog post today, Google said searches like the example above are "hard questions, and we’ve acquired Metaweb because we believe working together we’ll be able to provide better answers." Hopefully that means Google can integrate Metaweb's technology into their own search functions smoothly.
Google will also keep Freebase, the database that provides Metaweb with its list of "entities," alive and open:
Better yet, we plan to contribute to and further develop Freebase and would be delighted if other web companies use and contribute to the data. We believe that by improving Freebase, it will be a tremendous resource to make the web richer for everyone. And to the extent the web becomes a better place, this is good for webmasters and good for users.
Metaweb was founded by Danny Hillis, a computing legend who pioneered both the RAID disk array and parallel computing, both now standards. He was also a vice president at Disney, and took control of Metaweb once it spun out of Applied Minds in 2005. It's not clear if he'll be going to work at Google, but he would certainly be a major asset to the team at Mountain View.