The projects that were moved are some projects were we expect collaboration with other software developers (BMI, MMI). These tend to appreciate the benefits of faster commits, local history and the pull request workflow over the more complex model of having a local as well as a remote repository.
Some have asked us why we are not moving everything to git. We have quite some experience in teaching people for whom version management is not an everyday, but more a few times per year activity. Learning the difference between init, pull, clone, fork, update, fetch, sync is not everybody's cup of tea.
One of the nice features of porting your code to github is that it is easy to setup a doi. This is also available for datasets in OpenEarth. If you want to have code moved to the openearth github, or if you want to know something about making your data or code citeable, please consult Fedor Baart or Gerben de Boer.