Califa Library Group is building their own ebook platform, based on the Douglas County Model. They will use Adobe Content Server to manage DRM, use Vufind as an interface, and operate on a one-checkout-at-a-time model. They expect to have a platform and collection for (Califa consortium?) libraries to sign up to by Spring 2013 (northern hemisphere). Califa also aims to have an acquisitions catalogue built by the second year of the project, to facilitate libraries purchasing their own local content.
Califa provides updates on the progress of the project on their Califa products and news blog. This includes some technical details and the philosphy behind the service.