the umm-dev.org website is currently under construction. When being ready, the website will contain relevant stuff concerning UN/CEFACT’s Modeling Methodology (UMM) like papers, specs, comments from stakeholders and implementers, infos about implementations (e.g., http://ummaddin.blogspot.com/), best practices, development news, etc.).
We try to be online in about two weeks (approx. end of October) – so check back regularly.