Not just not GNU: they also ditch systemd for dinit, syslog-ng and a bunch of homegrown plumbing:
> We are also putting a lot of effort into writing fresh low-level plumbing. For example, Chimera comes with first-class and built-in support for user services and other things dependent on session tracking (such as a shared session bus), implemented from scratch thanks to our Turnstile project, finally bringing functionality previously only available on distributions using systemd. This is being implemented in a vendor-independent manner so that other distributions can adopt it.
> We are also putting a lot of effort into writing fresh low-level plumbing. For example, Chimera comes with first-class and built-in support for user services and other things dependent on session tracking (such as a shared session bus), implemented from scratch thanks to our Turnstile project, finally bringing functionality previously only available on distributions using systemd. This is being implemented in a vendor-independent manner so that other distributions can adopt it.