Machineflesh is the first book in the CG Challenge series featuring the artwork and techniques of artists participating the online CG Challenges organized by The CGSociety (www.cgsociety.org). Machineflesh comprises of tutorials and artwork from the contestants of the Machineflesh Challenge (16 March – 18 June 2004). Machineflesh is produced to the highest standard by the award-winning Ballistic Publishing team. 96 pages of the book are packed with surreal and fantastic computer imagery emerging from the world's most prominent community of digital artists. In addition to an incredible selection of artwork related to the Machineflesh contest theme, the book delves in-depth into eight of the winning entries for the CG Challenge contest. The Machineflesh Challenge (CG Challenge XV) run by CGNetworks from 16 March-18 June 2004 was sponsored by Boxx Technologies, Wacom, NVIDIA, Discreet, The Gnomon Workshop and Ballistic Publishing. The Challenge received over 1,400 entries in the 3D category and over 700 2D entries, making it almost twice as large as the previously run Challenge, and setting the record as the largest online art contest ever run! Combining two popular themes (characters and machines), contestants were tasked to create an image depicting a mechanically altered or enhanced organic lifeform.