The whole design was done for 100% with free software. The biggest part consists of custom software in Python, of course within the SPE editor. For the visual power I used PIL and pyCairo. From time to time also Gimp, Inkscape and Phatch helped quite a bit. All the developing and processing was done on GNU/Linux machines which were running Ubuntu/Debian. In the end I had to collaborate closely on location together with the technicians of the Royal Dutch Mint (coin factory). So all the last bits were done on my Asus Eee PC.