Atlas is two things: enhancements to individual open source projects ("pro" version if that helps), and a unification between our projects to give a full dev to prod pipeline.

Per open source project we have, it adds features on top of it we felt didn't fit within the scope of the open source project itself. Example: Vagrant box hosting, Vagrant share (requires a server), Packer builds, Packer artifact hosting, Consul UI, Consul alerts, Consul alert history, Terraform collaboration, Terraform state storage, Terraform run locks, GitHub triggering Terraform, etc. These are all features that enhance an individual HashiCorp project. I'm not going to explain each here, since they're explained in the blog post and of course expect an understanding of that individual project.

Then, Atlas unifies them: code push (Git, CI, etc.) triggers an automatic Packer build which triggers a Terraform plan which triggers a Slack message asking for approval to deploy which can then be deployed with a single button which then causes the Consul UI to update with the latest info.

You can do this with our open source, purely, and many do. This was the inspiration behind Atlas: the companies adopting our open source projects want a complete story, and they're building it on their own, but they'd rather buy it from us. Atlas is us delivering that full dev to prod story.

If you're a HashiCorp user, Atlas is valuable if you're using an indivual project OR if you're looking for a complete deployment solution.

I hope this helps a lot more.