CircleCI aims to take automation of tests and deployments to the next level, whether you work with web, mobile, containers, macOS or Windows. The platform supports build, test and deployment pipelines in the cloud or on self-hosted runners and provides flexible execution environments - for example Docker containers, Linux VMs, macOS or Windows.
One of its strengths is tight integration with popular version control systems (like GitHub and Bitbucket) and quick onboarding via a .circleci/config.yml file. The platform also offers reusable building blocks called "Orbs" to simplify pipelines and integrations.
There are generous free tiers for open-source projects, making CircleCI attractive for smaller projects and community-driven tools as well.
