The Linux distribution ecosystem is pretty set, with Red Hat and Canonical in the leadership positions, followed closely by SuSe and home brews from the likes of IBM and other major vendors. Even Microsoft has its own distro for Azure users.
And then there is Cumulus Networks, which specializes in networking software. It just released Cumulus Linux 4.0 and NetQ 2.4, its cloud network deployment and management console. With this release, Cumulus is claiming its Linux is its most stable and reliable software stack yet and NetQ is the most comprehensive end-to-end network automation product.