"Seeks", a similar and very promising project

There is a similar project called http://www.seeks-project.info/site. For now they are operating as a decentralized meta-search engine, re-using other search engines, I guess because they didn't perceived the crawling part of the job as being the one that adds the most value. But I wouldn't be surprised that a longer term goal would be to have their own crawling services as well.

There are several seeks node that are up and running at the moment. You can consider installing your own, or using an existing one just for testing.

I personally use the node http://www.seeks.fr.