The play platform is web app development made as simple as possible (but no simpler).
The platform provides an editor, built in automatic version control and collaboration, continuous live preview, offline development, importing code from npm or github, and a build and deployment system.
You provide code in the languages of your choice, and the platform turns them into the forms that browsers understand, with no configuration needed.
As you develop, you get instantaneous feedback. Every change you make is saved, and can be replayed from any point in time.
If you publish your development session, other people can watch you code or collaborate with you.
When you are done, click a button in the development environment to deploy onto a server.
Note that most of the above is not implemented yet.