Citation Format
Noam Ross has come up with an elegant solution to the former problem:
Gabriel Devenyi and Christina Koch (eds), 63 authors including Noam Ross: "Software Carpentry: The Unix Shell" Software Carpentry Foundation, Version 5.3, May 2015, 10.5281/zenodo.27355.
I like this a lot: it includes the canonical form (editors, title, date, DOI) and avoids the issues associated with appearing to ascribe collaborations to whichever contributor's surname is lexically first. What we still don't know, though, is how to create entries in standard bibliographic formats like BibTeX so that they will produce this text when rendered. As distributed collaborations mediated by tools like GitHub become more common, that's a problem we're going to have to solve.