alt Hacker NewsNot sure, how active development is right now, but EdgeOS got forked from an open source devian based distro after that went commercial.
But EdgeOS was not the only fork, another one was VyOS (vyos.io). Pretty sure, that EdgeOS has done larger steps forward, especially, since it was bound to the hardware's developer.
The distribution was called Vyatta. VyOS is now very actively used and developed, it's way ahead of EdgeOS since that's been basically dead for years. EdgeOS was basically just a nice web UI over Vyatta but the one key point was that the EdgeRouters had hardware acceleration (Cavium CPU with offload, but Cavium got acquired by Marvell since) and only EdgeOS has the proprietary binary blob and integration that you need to use that on the EdgeRouter hardware.
So even though VyOS exists as the modern day Vyatta fork that is active and fully-featured, you can't really run it on the EdgeRouter hardware and since Ubiquiti stopped development, they're basically e-waste.
I still run one in a network but really shouldn't, since Ubiquiti are very rarely shipping security updates...