Since there were several requests for reusing the VISO ontology, we decided to move it to GitHub. A lean core version of VISO is currently build from the existing version and a few modules are already available. The existing version will remain for documentation purposes and serve as a base for the new version, which will start with a small set of stable concepts. Concepts that are required by VISO users are migrated incrementally.
If you decide to fork VISO, please use a sorted Turtle notation as it is offered, for example, by TopBraid Composer (Settings… -> Input/Output) in order to ease later merging of your extensions.