Apache Stratos!

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:

Google App Engine is a free* platform for developing and hosting web applications in Google-managed data centers. App Engine offers fast development and deployment; simple administration, with no need to worry about hardware, patches or backups; and effortless scalability.

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.

Simple PaaS for Java, Node, .Net, Ruby, PHP, MySQL, Mongo, PostgreSQL, and more. Freedom to move between IaaS at will with the easiest pricing in the cloud.

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.

Flynn is an open-source PaaS (Platform-as-a-Service) inspired by Heroku that simplifies deploying and maintaining applications.

In the blink of an eye deploy, update and scale your apps and their data in the cloud. Forget about system administration, focus on your app development.

Approachable PaaS solution based on Dokku - Docker powered software.