OPAL websites

- Code:         https://github.com/projekt-opal/doc#repositories
- Data:         https://hobbitdata.informatik.uni-leipzig.de/OPAL/
- Deliverables: http://projekt-opal.de/en/results/deliverables/
- Demo:         https://dice-research.org/OPAL-Demo
- Publications: https://dice-research.org/OPAL