I worked on Mantl for a while last year. To understand the difference you can see Mantl just as an opinionated coalition of tools for running microservices. So,

I worked on Mantl for a while last year. To understand the difference you can see Mantl just as an opinionated coalition of tools for running microservices. So, Mantl is not a thing but a collection of things (Mesos, Marathon, Consul, ELK stack, etc) put together using Ansible playbooks. Flynn is an actual product which, from what I can see, is also a collection of tools but these are written by the Flynn team themselves. I'm happy to answer any other question you might have about it.