The Open Service Interface Definitions (OSIDs) define a service-based architecture to promote software interoperability. The OSIDs are a set of interface specifications that describe how various software components interact using a variety of service interoperability patterns among its many service domains. It's a pile of paper.
The value of the OSIDs is only realized through working code.
This wiki contains documentation and examples on the use of OSIDs and the Okapia tools and runtime environment.