The question of what the seL4 license actually means, in particular, to which degree it may force deployer’s IP to be open-sourced (*), has come up repeatedly, and from informal discussions I realised that misconceptions abound.
I tried to clear up such confusion in a blog that I just posted: https://microkerneldude.wordpress.com/2019/12/09/what-does-sel4s-license-imp...
Enjoy, Gernot
(*) short answer: normally not at all!