...With these capabilities integrated in a single platform, advanced ePassport capabilities operate within a secure, proven PKIsystem with administration and distribution secured using the X.509 certificate architecture. Packaged in a unique...
http://news.thomasnet.com/fullstory/816154
...defines a programming interface for communicating with the PKIsystem. The Server API itself is implemented by the OpenXPKI...within the server's file system, building a redundant PKIsystem or a high-performance cluster of multiple nodes processing...
http://www.openca.info/docs/OpenXPKI-Architecture-Overview.pdf