Donald A. Tevault—but you can call him Donnie—got involved with Linux way back in 2006, and has been working with it ever since. He holds the Linux Professional Institute Level 3—Security certification, and the GIAC Incident Handler certification. Donnie is a professional Linux trainer, and thanks to the magic of the internet, teaches Linux classes literally the world over from the comfort of his living room. He's also a Linux security researcher for an IoT security company.