The use of open source environments for enterprise software projects is growing at an unprecedented rate, with notable peaks of interest among financial services and public sector organizations. Indeed, the adoption of open source software is growing at a great clip, with worldwide revenue from standalone open source software having reached $1.8 billion in 2006, according to recent calculations from IDC. That figure is expected to reach $5.8 billion by 2011, representing a compound annual growth rate of 26 percent. As a result, IDC is calling open source "the most significant, all-encompassing, and long-term trend that the software industry has seen since the early 1980s."