Apereo CAS is an open-source single sign-on and identity provider for web applications, offered in several languages. Alongside its development branch, the project maintains the 8.0.x and 7.3.x release lines; the latest release is version 8.0.2. Organisations install and operate CAS on their own servers or cloud infrastructure. The source code is available on GitHub under the Apache 2.0 licence.
CAS is managed by the Apereo Foundation, a non-stock nonprofit corporation incorporated in New Jersey, United States, with 501(c)(3) tax status. The foundation focuses on open-source software in higher education, and development and support are carried out by volunteers and contributors. Because the operator controls the deployment, a European university or public body can run CAS without sending authentication data to a provider outside the EU. Hosting, security updates and support remain the responsibility of the organisation.