Dokku

Dokku bills itself as the smallest PaaS implementation you've seen and that's probably true. Compared to Kubernetes, it is much smaller, both in footprint and in its community, which can be a challenge. With a smaller community and without a professional support option available, you might end up spending your time maintaining Dokku more than your application itself, which is against the promise of a PaaS.

Dokku, as a company, seem to be starting to offer a hosted option which is as of the time of writing is in Early Bird stage. However given the size of the company, you will be taking a high hosting risk with this option.

Dokku's simplicity appeals to hobbyists and side projects which could equally be attracted to the other providers' free offering. Given the history of container orchestration tools that have been abandoned by their developers (Flynn for example, comes to mind), Dokku might be a good option for a project that will never make it to production, but perhaps not much more.

Pros

• Small and easy to setup
• Can run on a single small server

Cons

• Small community with a high third-party risk
• Not as flexible as Docker Swarm or Kubernetes