My mind went to the Kerberos implementation, despite the slight spelling difference: https://github.com/heimdal/heimdal

There is also the tool for flashing Samsung Android phone firmware on Linux...

https://gitlab.com/BenjaminDobell/Heimdall

There’s also a db proxy you can run yourself that sits in front of Postgres and maybe others also named Heimdall. It’s like varnish for your db.