OpenEMPI is an open source implementation of an Enterprise Master Patient (EMPI) which is a repository that maintains a registry of all patients across an enterprise.
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HIEOS is an open source implementation of Integrating the Healthcare Enterprise (IHE) Cross Enterprise Document Sharing (XDS.b) and Cross Community Access (XCA) integration profiles.
The Open eHealth Integration Platform (IPF) provides interfaces for health-care related integration solutions. An prominent example of an healthcare-related use case of IPF is the implementation of interfaces for transactions specified in Integrating the Healthcare Enterprise (IHE) profiles.
IPF can be easily embedded into any Java application and additionally supports deployments inside OSGi environments.