The VieVS-VLBI module is available from GitHub: https://github.com/TUW-VieVS/VLBI
The most recent version of the software is now available for everyone without any registration and will be continuously updated on GitHub. It can be cloned and pulled using Git (a free and open source distributed version control system) or simply downloaded as ZIP.
Please refer to https://github.com/TUW-VieVS/VLBI/blob/develop/README.md to see how to get started.
All software parts are open source. Feel free to use and modify the source code according to your needs and in accordance with the terms of the GNU General Public License v3.0. We are open for comments, bug-reports and of course questions (if they cannot be solved using the documentations).