A little googling finds: http://research.microsoft.com/en-us/news/features/fsharp-041310.aspx http://research.microsoft.com/en-us/news/features/fsharp-041... "

A little googling finds: http://research.microsoft.com/en-us/news/features/fsharp-041310.aspx 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.