PMC
PCI Mezzanine Cards (PMC) are intended to be used where slim, parallel board mounting is required such as in single board computer host modules with the addition of expander cards or option cards The PMC may be mounted with instruments and panels that comply with the requirements of IEEE Std 1386 [1]
XMC
XMC is based on the VITA 42 family of specifications. TheXMC base specification introduces a new module format based on familiar PMC mechanicals and adds a new set of high-speed differential signaling connectors. The base specification provides a common set of definitions for physical characteristics of mod-ules, on which layered or “dot” specifications for implementation of specific switched serial fabric technology can be overlaid. VITA 42 specifications currently include: