The open source cloud landscape covers a lot of ground. Some platforms give you a full IaaS stack with their own API surface. Others sit on top of existing hypervisors. A few implement the AWS API so your existing tooling carries over unchanged. The right choice depends on what you're replacing, what your team already knows, and whether you can afford to rebuild your operational model from scratch.

This is a practical comparison of the main options in 2026, written from our own vantage point as one of them. We've tried to be honest about where each tool fits and where it doesn't.

OpenStack

OpenStack is the oldest and most battle-tested open source cloud platform available. It covers compute (Nova), object storage (Swift), networking (Neutron), block storage (Cinder), identity (Keystone), and a dozen other services, each maintained as a separate project under the OpenStack Foundation.…