I've recently uploaded my work on Nostos to Github. I'm really excited about finally finishing it and urge you to check it out.
Nostos simplifies library circulation systems by integrating transactions from disparate systems. Nostos was originally developed to integrate a library's interlibary loan system with its integrated library system. This lets libraries to manage circulation within a single system, allowing patrons to check a single account and simplifying their experience. It also improves administration in that circulation notifications, policies, reporting, and auditing originate from a single system, which is most likely the library's most powerful/mature circulation system.
Nostos is built to be a modular system. Thus, you must install at minimum one source and one target driver. Currently, Nostos is prebuilt for Illiad and Voyager, however, I plan to pull those drivers out as separate gems to make development easier for other systems.
Currently, Nostos only creates records in a target for each source. I have already begun development on enhancements that further keep their circulation status in sync for example automatically charging items in Illiad when they are charged in Voyager, automatically detecting mismatched due dates, and automatically detecting items returned in Illiad but still charged in Voyager. I hope to put those in a nice easy to use web interface.
As a tangent, I've created a couple supporting gems including activerecord-illiad-adapter to help interface with the Illiad database and voyager-sip to interface with Voyager's SIP server. I implemented the bare minimum for each, however I plan to extend them as I see a need.
Cheers,