Hi 
It's not quite the same as an off-shoot. An off-shoot would be more like a
little branch budding off the main trunk.
What we have is 2 versions of the original project. Both have people and
resources that date far back, sometimes to before the existence of either
branch. For one project it's more like they just had a name change and a
bit of work on modernising the infrastructure but it's mostly "business as
usual".
With LibreOffice it was fairly quickly the case that almost the entire
community, almost all the devs and almost all the organisations and
companies all moved to LibreOffice. All that was left at OpenOffice was
the name, trademark, the websites and forums and a very few of the
companies and some of the paid devs.
Of course there were and still are people who contribute to both projects.
With MariaDb one or a few of the main original devs moved from MySql to
MariaDb and the others mostly left. Oracle had to re-staff. Most of the
community also moved. So really what was left behind didn't bear much
resemblance to MySql at all. Most of what people think of as MySql had
really just had a name-change.
Regards from
Tom 