(Our licensing is still uncertain because this is an experimental project -- using a code hosting service to develop scientific documents. Our guarantee is that the license will be open source/open access of some sort, but we are not yet firmly decided which. Options being considered include: (i) Creative Commons - Attribution (standard Open Access publishing license) (ii) Creative Commons - Attribution Share Alike (require derivative works to be similarly open) (iii) GNU Affero GPLv3 (an intriguing possibility: the implication here is that document source and image files must be made available when the document is redistributed). Advice, thoughts and comments are welcome. Potential contributors are requested to kindly consider the above licensing options and whether they would be happy with all or any of them.)