I'm pretty sure they use Yahoo BOSS, plus some in-house stuff that merges info from trusted sites like Wikipedia. Yahoo's results are pretty good, though I hope that BOSS-based sites survive whatever the fallout of the Yahoo-MS search deal ends up being.
Personally I've found that the extra features on top of Yahoo's results that DDG gives aren't usually very useful, but it's nice and fast with a simple, usable interface. For the few weeks I had it as my Firefox search box default, the only thing I felt was missing was how Google includes results from Google News and Image Search right on your search results page.
Also, the founder of DDG posts here on HN, which is one reason why you'll hear about it around here more often than other places.
Curious, what do you think the plethora of other alternatives are? I've been pretty unimpressed by the small search engines trying to use their own indexes (Cuill) and even less impressed by the "human-powered" engines (Mahalo). I haven't seen anyone else really come close to Google, Yahoo, Bing, and Ask.
DDG founder here. We started out solely with our own crawler, which we still use for various things, e.g. finding and removing 50 million+ parked/spam domains. But we do use Yahoo BOSS as well.
However, we do not use BOSS straight up. We re-rank, omit, edit, merge, etc. in ways (I think and hope) yield much more relevant results, especially for more specific queries.
The Yahoo/MS search deal shouldn't effect us. We already have Bing in place as a backup and could easily switch to Ask's feed as well. We treat them as somewhat of a commodity, i.e. an output of the Web link graph, with our ranking stuff on top doing the important "last mile" work.
Personally I've found that the extra features on top of Yahoo's results that DDG gives aren't usually very useful, but it's nice and fast with a simple, usable interface. For the few weeks I had it as my Firefox search box default, the only thing I felt was missing was how Google includes results from Google News and Image Search right on your search results page.
Also, the founder of DDG posts here on HN, which is one reason why you'll hear about it around here more often than other places.
Curious, what do you think the plethora of other alternatives are? I've been pretty unimpressed by the small search engines trying to use their own indexes (Cuill) and even less impressed by the "human-powered" engines (Mahalo). I haven't seen anyone else really come close to Google, Yahoo, Bing, and Ask.