Comment by 4suc
https://kernkonzept.com/ is a company developing the L4Re OS. The company is a spinoff from the TU Dresden Operating Systems group. Afaik their main customer is the automotive industry which uses their hypervisor. L4Re is also certified for all kinds of government secrecy levels, so I would assume they have some users in that area.
Two products for one-way data transfer, based on L4Re:
- https://www.genua.eu/it-security-solutions/data-diode-cyber-... - https://www.genua.eu/it-security-solutions/data-diode-vs-dio...
Disclaimer: I work for genua, the maker of these products.