Maybe they're using seL4?
I do not know of their design, but I know some helenos devs are involved, so it's sure to be a proper microkernel multiserver system.
I do not know of their design, but I know some helenos devs are involved, so it's sure to be a proper microkernel multiserver system.
seL4 is just the kernel. Linux can have software with a range of licenses in userspace, so can seL4.
A system based on seL4 would be built as a bunch of services running under seL4, rather than by modifying seL4.