Hi Holger,
The Dataverse Desktop edition is primarily designed for individual use so the collaboration mechanism there is limited to exporting - sharing - and importing data flows and nodes (i.e. using .lna files).
The Dataverse Server editions provide the ability to use the Public Documents location to share data flows and nodes with other Dataverse users accessing the same Server instance. However, the current release does not provide collaborative versioning of assets such as you would find in a version control system such as git/ subversion, etc. We are looking at how to enhance our collaborative versioning capabilities in future releases of our enterprise server editions. Obviously, in the short-run, any Dataverse assets can still be exported and then stored in a versioned repository to provide rudimentary version control but it does not provide merge capabilities.
Leveraging existing Dataverse capabilities such as Composites and library nodes may also provide opportunities for partitioning an overall project into multiple components that could be worked on in parallel by team members and then integrated into a versioned 'build'.
Regards,
Adrian