Ars Technica: Microsoft open sources algorithm that gives Bing some of its smarts. “Microsoft has released today the SPTAG [Space Partition Tree and Graph] algorithm as MIT-licensed open source on GitHub. This code is proven and production-grade, used to answer questions in Bing. Developers can use this algorithm to search their own sets of vectors and do so quickly: a single machine can handle 250 million vectors and answer 1,000 queries per second. There are some samples and explanations in Microsoft’s AI Lab, and Azure will have a service using the same algorithms.”