He is known for his books, especially on the Linux kernel, which has been translated into several different languages. His Linux experience reaches back to 1997, with a spectrum from Linux bring-up on special purpose embedded devices to scientific high performance computing. Before joining Siemens, he obtained a doctoral degree in quantum physics from the Max Planck Institute for the Science of Light. His publication record ranges from peer-reviewed scientific journals to community-driven online magazines; he has spoken at open and closed conferences and events, and teaches at academic institutions.