The search engine is actually a mash-up of several other sites like Wikipedia, About, Bing, and Yahoo. DuckDuckGo uses so-called Zero Click search results to guess what youare looking for and give it to you directly in your search results.

I've been testing DuckDuckGo for a few days now, and I must say i'm impressed; it has indexed quite a lot by now (i can't see how recent the result pages are, as there is no view-cached option), and it's quite fast as well. However, the most remarkable thing about DuckDuckGo is the fact that the entire search engine is built upon open source building blocks. It's platform is FreeBSD and it uses perl and postgresql, for example.

According to DuckDuckGo's developer, Gabriel Weinberg, the software stack looks like this:

- Web Server: Nginix
- Cache: Memcached and Solr
- Database: PostgreSQL
- Primary Language: Perl
- Operating System: FreeBSD for the main site or Ubuntu for Amazon EC2 failover images


All and all it's a very nice search engine, though I really miss a view-cached option and a DuckDuckGo Images section.