The current version of XMCDA is 3.1.1.
It is available as usual as a XML schema, at: XMCDA-3.1.1.xsd.
However, it is not the operational version of XMCDA yet, and XMCDA
v2.2.3 is still the one on which web-services and diviz operate.
The reason is that switching from v2.x to v3.x is a huge step for all of us.
Roadmap
The following roadmap has been adopted:
Propose a reference implementation of XMCDA v3.x
This implementation should be available to (at the minimum) the following languages: Java, R and Python.
This implementation should be able to translate from one version to another, using the principle of the maximum efforts (bot versions are not compatible so certain things cannot be translated).
Develop, experiment and validate a program wrapper so the current hundred or so web-services are available to accept and produce XMCDA v3.1.1 files (problems that may arise due to the incompatibility of the two XMCDA versions will be addressed with the web-services authors directly).
When this is done, diviz will entirely switch to XMCDA 3.x
At this point, XMCDA v2.x will officially be abandoned on the operational level and XMCDA v3.x will be fully in charge of conveying out MCDA data. Note that at the time of the switch, the web-services and diviz operating with XMCDA v2.x will not be immediately shut down, but they we will be freezed and left for use for at least 6 months, so that everyone has enough time to handle the transition.