My new book will be published Open Access, and I also aim only to use open-source tools as part of the writing process. The most challenging has been to figure out how to make nice-looking illustrations. Parts of the book are based on the Ph.D. dissertation that I wrote a long time ago. I wrote that on a MacBook and made all the illustrations in OmniGraffle. While it was quite easy to make the switch to Ubuntu in general, OmniGraffle has been one of the few programs I have really missed in the Linux world.