Blekko's alternative search engine -- a $24 million venture-backed
project that's been three years in the making -- is today launching its
public beta.
blekko | slashtag search

With the official rollout, Blekko is also releasing several new features
designed for both mainstream and the site's super users.

As you may recall, Blekko is designed to eliminate spam search results,
allowing users to search just a subset of the web through its
proprietary slashtag technology.
[...]
Health, lyric and financial queries on Google or Bing, for instance,
will return results dominated by poor quality content farms or
malware-hosting sites.

Those same searches on Blekko yield results only from high quality sites.
[...]
Alternative search engine Blekko launches - CNN.com