DCM4CHEE is a first-class medical image archive with one of the most robust and mature DICOM and IHE implementations anywhere in the world.

From the dcm4chee wiki:

The components of dcm4chee work together to provide you with a reference implementation of many IHE actors and Integration Profiles. I use the term “reference implementation” not because the system is purely academic. On the contrary, it is capable of (and indeed is) deployed in production at many sites around the world. The term is used because no other system in the world provides such a complete and well designed implementation of so much IHE-defined functionality in an open source fashion.

We can’t agree more.  Installed as mission critical software in hundreds if not thousands of hospitals around the world, DCM4CHEE is a proven solution to very read problems.