Patrick Hood-Daniel is a hobbyist. In his day-job, he is an urban designer trained in architecture at the University of Miami, School of Architecture and urban design at the University of California at Berkeley. Patrick also serves as a college level instructor for various creative technical fields of mechanical engineering, architectural design, industrial design, civil engineering, materials and manufacturing, urban design and construction management. But in his spare time, Patrick is a hobbyist who puts skills from a previous career as a computer programmer to good use in building and operating computer numerical controlled (CNC) fabrication machines. He is the creative force behind www.buildyourcnc.com and is well known for designing CNC machines that can be built at low cost by normal people, and without any special or expensive tools.

James Floyd Kelly is a freelance writer living in Atlanta, Georgia, with degrees in English and Industrial Engineering. James has written on topics including LEGO robotics, building custom computers and free software. His books include Don't Spend a Dime: The Path to Low-Cost Computing, Ubuntu on a Dime, and LEGO MINDSTORMS NXT 2.0: The King's Treasure, the sequel to LEGO MINDSTORMS NXT: The Mayan Adventure. He is also the creator and editor-in-chief of the most popular NXT robotics blog, www.thenxtstep.com, with over 45,000 readers visiting each month.