Rolling release

A rolling release is a release model in which software is installed once and then updated perpetually, with new versions arriving as a continuous stream of small, frequent updates rather than as periodic discrete releases. It is also called a rolling update. The model is the opposite of a point release (or fixed release) model, in which a product is shipped as a sequence of numbered versions that each replace their predecessor, as with the biannual releases of Ubuntu Linux.

Although it is sometimes loosely described as continuous delivery, rolling release is better understood as a distribution and versioning model rather than a development practice. The two ideas are related but distinct, and the garden covers continuous delivery separately.

A rolling release is typically implemented using small and frequent updates. Merely shipping frequent updates does not, however, make a project a rolling release. The defining trait is the developers' commitment to a single code branch with no discrete versions, rather than a series of separately maintained releases. Updates are usually delivered to end users by a package manager pulling new builds from a remote software repository, often via a download mirror.

Rolling releases are most commonly associated with Linux distributions, where the model is popular for cutting-edge distros such as Arch Linux, Gentoo, and openSUSE Tumbleweed. There, new packages and significant changes can arrive at any time, in contrast to a fixed-release distribution that only receives security and bugfix updates between major releases. The model is not exclusive to operating systems, though; some distributed databases, for example, support rolling releases too.

Not to be confused with rolling deployments, which is a deployment strategy for updating running server applications without downtime. A rolling release is also distinct from a staged (or staggered) rollout, in which a single update is gradually released to an increasing percentage of users for testing or bandwidth reasons.