Atlantis vs Pivotal Web Services (PWS): What are the differences?
Atlantis: Open Source PaaS Built on Docker, by Ooyala. Atlantis is an Open Source PaaS for HTTP applications built on Docker and written in Go. It makes it easy to build and deploy applications in a safe, repeatable fashion, and flexibly route requests to the appropriate containers; Pivotal Web Services (PWS): Deploy, Update and Scale Applications On-Demand. Pivotal Web Services is a public cloud version of the widely supported Open Source Cloud Foundry PaaS. PWS makes is an ideal platform for the rapid deployment, easy scaling and binding of third party apps for Java, PHP, Ruby, GO and Python apps. Focus on apps not dev ops.
Atlantis and Pivotal Web Services (PWS) belong to "Platform as a Service" category of the tech stack.
Atlantis is an open source tool with 381 GitHub stars and 33 GitHub forks. Here's a link to Atlantis's open source repository on GitHub.