Ubicloud: Open, Free, and Portable Cloud

Cloud providers rented out this compute on top of their infrastructure.

This seems to provide a similar abstraction on top of bare metal, kind of like openstack.

You can think of Ubicloud as software that takes bare metal servers as its input, and provides VMs and other cloud infrastructure services as its output. You can self-host Ubicloud on your own hardware, or use it as a managed service.

Comments below are on point: Compared to OpenStack, Ubicloud is simpler, comes with a managed service that you can use in minutes (vs days/weeks), and provides more services such as managed databases.

Compared to Kubernetes, Ubicloud covers layers both above and below Kubernetes. For example, running K8s on AWS/Azure/GCP depends on having VMs where the pods can run on. Similarly, running a managed database service on K8s requires much more than the basic K8s service itself.

Put differently, all major cloud providers have proprietary software similar in purpose to Ubicloud, which they use to provide their core cloud services. Using AWS as an example, services like EC2, RDS for managed Postgres, or EKS for managed Kubernetes, all run on this type of software. Ubicloud makes this software open source, and allows it to run anywhere--not just on AWS data centers.