AppScale is an open source version of Google's AppEngine. While I like the opensource view of this platform there are many advantages to deploying on the google version. First of all I'm just not sure which direction the development went. Was AppScale first or AppEngine. Then there are all the tools, consoles, dashboards, and integrated services... but you're going to pay for that. Granted scale is everything but there is something to be said about the development environment, designs, and the discipline it invokes. (incomplete because there are shards of for profit and platform lock-in)
Bitnami - this platform has been around a long time. I remember the ole days when it was the poor man's multi-tenant platform just prior to the domain landrush. The platform has grown to include many different types of packaging. What makes it ideal is that the platform is separate from the applications.
VMware is acquiring Bitnami to accelerate application delivery for multi-cloud and Kubernetes and expand Bitnami adoption in the enterprise.Apcera - I do not know where is company is any more. It had some novel solutions for managing security but the platform was very expensive. Skipping it for mow.
Drupal - it's a CMS but I'm not sure how it works except for the multi-tenant/application thing.
Joyent - stupid expensive so never mind.
Rancher - I like rancher. That they seem t be pivoting from 1.0 (cattle and swarm) to k8s and k3s suggests that they know something and are not talking, however, my problem with them is that they send a lot of time talking about deploy and not so much time talking about disaster recovery.
Deis - I thought this project was acquired by docker, however, the domain redirects to Azure.
Kitematic - development tool seems to be acquired by docker.
Heroku - Kinda like bitnami. This article points out some interesting ideas on why not.
Unless you want to build a platform of your own having a platform let's you focus on the things that matter.