"vs." (versus) is misleading;
TLDR Fly.io likes and claims alignment with MRSK, which is 37signals/DHH's new mechanism for managing dockerized apps with a strong "get off the cloud, run it locally" story.
It’s like comparing AWS with Chef. Maybe there’s some overlap in philosophy, but that’s about it. Maybe fly.io is just using it as a way to do a bit of marketing.
MRSK is a direct competitor to Fly's own orchestrator, and is meant for use when hosting on your own hardware or on a VM rented from an infrastructure provider. So it's still a "use either A or B" situation.
I guess a better title would be – Hosting on the Fly.io platform vs. on your own servers/VMs with MRSK.
I'd love it if all 'vs' and competitive marketing was this good.