Hey there -- so this is a bit of a terminological thing, but we don't consider balenaEngine to be a docker fork -- it's a sibling project descending from the Moby Project, just like Docker, and of course highly copmpatible with Docker. The things we've done in balenaEngine aren't things that Docker would do. Shrinking the size to a quarter, removing Swarm, adding container deltas, changing the tradeoffs around durability -- most of the changes we have made relate to the embedded use case. As such, we intend to keep evolving balenaEngine alongside Docker, also because it's important for us to control the size of the binary. It goes into our root partition, and if Docker keeps adding things to their engine, we can't have that variable affect our ability to update devices.

We've done a lot of things to make sure balenaEngine is rock solid in an embedded environment, and our fleetOps team is pretty hardcore in helping customers get out of hard situations (which help us further evolve the OS and the engine to avoid those by default).