Hi,
A new opensource viewpoint is now available ! 
Darc Viewpoint (Cybersecurity Assets & Threats Modeling analysis)
Capella Darc add-on is to support effective co-engineering between systems and cybersecurity engineers teams when performing the following tasks:
- Identify assets & trust boundaries
- Identify threats
- Characterize security needs
User Manual
Look at User Manual
Threat Diagram
Architecture Blank Diagram
Download
Compatible with Capella 5.2 and Capella 6.x
Download release v2.1.1 and sample model for 6.0 or upcoming 6.1
Download release v2.0.1 and sample model for 5.2
Release Notes comparing this version to previouses prototypes
Regards
Philippe