machaut writes: "Twitter, one of the highest profile Ruby on Rails-backed websites on the internet, has in the past year started replacing some of their Ruby infrastructure with an emerging language called Scala. Although they still prefer Ruby on Rails for user-facing web applications, they have started replacing Ruby daemon servers with Scala alternatives, and plan to eventually serve API requests, which comprise the majority of their traffic, with Scala not Ruby. This week several articles have appeared that discuss this shift at Twitter. A technical interview of three Twitter developers was published on Artima. One of those developers, Alex Payne, Twitter's API lead, gave a talk on this subject at the Web 2.0 Expo this week. His talk was covered in articles at Technology Review, Internet Evolution, and The Register."