What is Release-to-Manufacturing (RTM) Version?

The release-to-manufacturing (RTM) version, also called the golden master build (GM) version, refers to the version of software which is ready to be delivered for final release. The RTM version is typically released after the pre-alpha, alpha, beta, and release candidate versions. RTM is usually released before the general availability (GA) version is released to the public. As an example, when Apple releases an operating system (OS), they use the RTM version to make all future copies of the OS.