Most probably the author knows this but there are some photos and information here [1]. His grandfather is a member of "The Righteous Among the Nations" [2].
Thanks for sharing this, I was not aware of it and I’m currently in the process of learning Hebrew, dealing with the intersection of (Jewish and Christian) culture and technology.
One example is a GPT version [1] fine tuned on texts of Sefaria [2].
The initiator was in direct contact with Sam Altman to kickstart it. (Personal communication).
Good find - Henk and Hein were actually cousins of my grandfather. His eldest two sons (my uncles) were also involved with the resistance, though this only came out recently.
[1] https://www.yadvashem.org/righteous/stories/sietsma.html
[2] https://www.yadvashem.org/righteous.html