This looks great! At a previous job we had a fork of Jupyter notebooks that were used this way by some teams. I see that remote execution is on the roadmap, but was also wondering if you'll have some form of parallel remote execution as well (ie one runbook run across 10 or 100 VMs similar to parallel ssh). Definitely more complicated than single execution, but potentially very powerful for debugging fleets where you don't have Chef or Ansible. I guess the alternative is to just have the runbook run locally but run pssh in some commands to get a similar result.