OffiServ API

OffiServ is a service that delivers to Small and Medium Enterprises a set of processes solving common office problems and impediments, without a necessity to design own processes or to buy BPM software. By using OffiServ companies can improve their employees efficiency. OffiServ offers process support in service desk, resources, purchasing, employee address book, employee leaves, HR services and secretary.
OffiServ API is an open API that allows access to the service using programming interface. Developers can acquire data from the service, manipulate it and also invoke actions. OffiServ API is based on REST model and uses JSON for data formats.

It's currently in Beta.