Now more than ever, the development of the Linux kernel is a matter for the professionals, as unpaid volunteer contributions to the project reached their lowest recorded levels in the latest Who Writes Linux report, which was released today. According to the report, which is compiled by the Linux Foundation, just 11.8% of kernel development last year was done by unpaid volunteers – a 19% downturn from the 2012 figure of 14.6%. The foundation says that the downward trend in volunteer contributions has been present for years.