- I don't think SeL4 is "defunct" even though CSIRO's decision on the Trustworthy Systems group was profoundly incompetent; here's a relatively recent post from Gernot Heiser: https://microkerneldude.org/2021/09/28/where-is-sel4-heading...

Also: https://sel4.systems/news/2021

Do you know more that would substantiate defunct-ness?

- Your comment also reinforces my point: if aerospace seeks to be more rigorous, then more in aerospace should be figuring out how to shore up development of SeL4. Instead, they continue with no vision as to what should one day replace things like VxWorks.