Linux Kernel Contributors

Consistent with what I found in my research for my undergraduate economics thesis, "A Theoretical Analysis of the Efficiencies of Software Development Models," virtualization.info cites Citrix and VMWare as being ranked as the #12 and #20 (respectively) contributors to the newest Linux Kernel (2.6.34). Although this may seem initially counterintuitive that two proprietary software development firms are such large contributors to open source software, it is consistent with my research findings that the largest contributors to open source software communities are in fact private, for-profit industry firms.