You would think so considering the creator constantly calls it that, but it is merely source-available. This has been repeatedly brought up along with other very questionable license decisions [0]. The charitable interpretation is that the creator is very confused about what open source is and isn't.

Here's a summary:

- The project is licensed under the "Corridor Key License" [1], which is CC BY-NC-SA 4.0 with extra clauses that permit commercial use of you have their blessing (That's right, CC BY-NC with commercial use allowed).

- CC licenses should not be used for software, and the non-commercial restrictions make this project not open source.

- This project is based on Hiera, which licenses its weights under CC BY-NC 4.0 [2]. Again, non-commercial. He is selling this.

- The license was changed a few times after the community rewrote large parts of this project. The contributors should've retained their copyright to their contributed code as there was no CLA or similar, but to my knowledge their code was relicensed without their consent.

[0] https://github.com/nikopueringer/CorridorKey/issues?q=licens...

[1] https://github.com/nikopueringer/CorridorKey/blob/main/LICEN...

[2] https://github.com/nikopueringer/CorridorKey/issues/152