Flynn!

Heroku is a cloud application platform for Ruby, Rails, Node.js, Java, Python, Scala and Clojure web apps. Everything you need to build, run, and scale:

Last.Backend is a cloud platform based on bare-metal servers around the world with fastest SSD disks. Last.Backend enables developers to focus on writing great cloud-based applications without having to worry about managing the underlying infrastructure.

Dokku-alt is a Docker powered mini-Heroku. The smallest PaaS implementation you've ever seen. It's a fork of original dokku. The idea behind this fork is to provide complete solution with plugins covering most of use-cases which are stable and well tested.

Tsuru is an extensible and open source Platform as a Service software.

Apache Stratos is a highly-extensible Platform-as-a-Service (PaaS) framework that helps run Apache Tomcat, PHP, and MySQL applications and can be extended to support many more environments on all major cloud infrastructures. For developers, Stratos provides a cloud-based environment for developing, testing, and running scalable applications. IT providers benefit from high utilization rates, automated resource management, and platform-wide insight including monitoring and billing.