https://github.com/gocircuit/circuit

I too am having a hard time trying to figure out exactly where circuit fits vs. other technology.

It wasn't immediately clear to me if circuit launches the apps, or if it can start new instances if the current ones fail, or if it can grow the cluster if demand is the current utilization is too high, or what.

How does this help me vs. writing a script in (the shell, some other orchestration tool, etc)?

How much of the configuration does it handle? Does it replace etcd?

Those are questions I could ideally answer myself by exploring the documentation links on the main page. Where / how does it store its own state?

Edit: There is a comparison with Consul on the wiki:

https://github.com/gocircuit/circuit/wiki/Circuit-vs.-Consul

The general idea being that it creates a virtual operating system across multiple physical or virtual "hosts" and allocates application stacks (like containers, maybe) compute/memory/storage as required. It ideally handles fault tolerance and load balancing gracefully too.