Diomidis Spinellis writes: "We hear a lot about the adoption of open source software, but when I was asked to provide hard evidence there was little I could find. In a recently article we tried to fill this gap by examining the type of software the US Fortune 1000 companies use in their web-facing operations. Our study shows that the adoption of OSS in large US companies is significant and is increasing over time through a low-churn transition, advancing from applications to platforms, and influenced by network effects. The adoption is likelier in larger organizations and is associated with IT and knowledge-intensive work, operating efficiencies, and less productive employees. Yet, the results were not what I was expecting."