There was a nationwide project in the UK a number of years ago and i believe there have been several more but i don't know the details.
Having said that, it is a very wide ranging standard so there is no guarantee that the pieces you want are covered by that project.
Also, when i last looked at this several years ago, it was widely agreed that the standard was dead, having slowly collapsed under its own weight (although some elements live on in other standards).
I don't know if ebXML has been revived in recent years, but I doubt it. Why are you interested in it?