ReleaseCandidate

Release candidate, often abbreviated RC, is a pre-release version of software issued for final testing before the official public release. It is intended to validate stability, performance, and compatibility across real-world environments and user workloads, beyond what internal QA can cover.

RCs are typically feature-complete and undergo a code freeze, meaning no new features are added after an RC is issued. The focus shifts to identifying and fixing remaining bugs, regressions, or edge-case issues. Deployment of an RC may include release notes that document changes, known issues, and compatibility considerations. Feedback is collected from testers, users, and automated systems to determine whether the product is ready for general availability or if additional RCs are necessary.

The RC lifecycle often includes multiple iterations, such as RC1, RC2, and so on. An RC becomes the final release if no critical issues are found, or it may lead to additional RCs if significant problems are discovered. In some workflows, minor fixes or backports may be released as patches without changing the RC designation.

In practice, release candidates are used across software projects, including open-source and commercial software. They influence downstream processes such as packaging, distribution, and installation, and they help coordinate timing with release management, documentation, and downstream vendors. The RC concept helps balance the need for broad testing with the goal of delivering a stable, user-ready product.