I can try and help from the standard perspective, not in terms of the implementation, though.
As I understand so far that the OneM2M is some kind of the improvement of the ETSI M2M standard.
Technically speaking, the principles are the same, the key Resources are still Applications, Containers and Access Rights (ACP in oneM2M). And the principle of separation of the semantic treatment from the platform is still the same. So de facto Release 1 of oneM2M is a sort of "Release 3" of ETSI M2M.
Only thing though, they are not backward compatible.
Hope this helps.