Bing is now powering Yahoo in US & Canada

I think the deal's for 10 years so it'll be a long time before we find out.

But my god is it difficult to get an adcenter api key from Microsoft. But that's a completely different rant (why do all the major search engines make it so damn hard to spend money with them?).

I expect under the hood Bing is Azure.

Parts of Bing are (were?) backed by Hadoop thanks to Microsoft's purchase of Powerset - all their NLP search technology ran on Hadoop.

A little googling finds: http://research.microsoft.com/en-us/news/features/fsharp-041...

"We’ve also seen fantastic applications in server-side data analysis, including in parts of the Bing ad delivery and analysis pipeline. F# seems a particularly good language for programmatic machine learning."

I think that is just one small part of the Bing system though.

Bing uses a lot of Microsoft technologies including C# and .NET framework languages but as with many large services (or sets of services in this case) the components crawling, processing, indexing and serving content are written in a variety of languages including C, C++, etc and are managed by a myriad of tools languages that support features.

One that I use is http://www.opensiteexplorer.org from http://www.seomoz.org (disclosure: you need a paid account to get the most out of it and we are business partners of SEOmoz).

Probably not. In fact, even Google returns different results for itself sometimes, depending on the servers your search request gets routed through.

DuckDuckGo is just an interface to Bing.

Not to take anything away from the guys, but it is not fair to lineup DuckDuckGo aside Google, Bing and Cuil. It’s simply misleading, yes DuckDuckGo is an interface to search engines.

http://yandex.com (Russian search engine) recently launched global English search.

There's the Chinese http://www.baidu.com/ .