The Open Monograph Press (OMP) software-based system has been released. It’s similar to the various open ejournal publishing systems, but it’s for open scholarly ebooks…
“OMP is an open source software platform for managing the editorial workflow required to see monographs, edited volumes and, scholarly editions through internal and external review, editing, cataloguing, production, and publication. OMP will operate, as well, as a press website with catalog, distribution, and sales capacities.”
Final production formats are currently print, PDF, and ePub. No sign of elegantly formatted HTML chapters / Kindle .MOBI yet, but hopefully that will come in time.