hurd isn't even interesting. seL4 is faster, has production applications, and is formally verified. you can even use seL4 as a base platform in genode[0].

[0]: https://genode.org/documentation/platforms/index

gnu hurd was released in 2015, but very few people are working on it i'm afraid. https://www.gnu.org/software/hurd/news/2015-04-29-debian_gnu...