"For any given search, there is usually a vertical search engine out there that does a better job at answering it than a general search engine," the project explains. "Our long-term goal is to get you information from that best source, ideally in instant answer form."
I decided to try to replicate some of the reported problematic results on my own by doing a few parallel searches on Google and DuckDuckGo.
A Mini Test
Not including sponsored results, a Google search on the term "office software," for example, led to results that began with OpenOffice.org first, Microsoft Office second, and Wikipedia's "Office Suite" page third. LibreOffice did not appear in the top 11 results.
On DuckDuckGo, the very same search produced results that also began with OpenOffice.org and then went on to Freebyte.com/office in second place, an OfficeMax page third, and Microsoft's home page fourth. LibreOffice did not appear in the top 11 results for this search, either.
Searching instead on "office suite"--one of the terms Muktware used--both search engines' top result is OpenOffice.org once again. LibreOffice appears in 13th place on Google and 37th place on DuckDuckGo.
A search on "open source operating system," meanwhile, kicks off with Ubuntu on Google, followed by the Wikipedia page on the topic. The DuckDuckGo results began with the Wikipedia page, followed by several download sites. Android, interestingly, was the first project page--occupying the sixth spot--and the TinyOS page wasn't much further down. The Ubuntu page, however, wasn't anywhere in close sight.
It's interesting that this has come up just as peer-to-peer search engine YaCy is released.
Still, with such mixed results in what was admittedly a very small and unscientific test, I have trouble believing that there's a systematic bias or filtering effort going on here--particularly since OpenOffice so clearly dominated both search engines' results in that category. If Microsoft were exerting any such effort, I suspect that would be among the first results to get filtered out.