# Docker Release Process
 
 This document describes how the Docker project is released. The Docker project
 release process targets the Engine, Compose, Kitematic, Machine, Swarm,
 Distribution, Notary and their underlying dependencies (libnetwork, libkv,
 etc...).
 
 Step-by-step technical details of the process are described in 
 [RELEASE-CHECKLIST.md](https://github.com/docker/docker/blob/master/project/RELEASE-CHECKLIST.md).
 
 ## Release cycle
 
 The Docker project follows a **time-based release cycle** and ships every nine
 weeks. A release cycle starts the same day the previous release cycle ends.
 
 The first six weeks of the cycle are dedicated to development and review. During
 this phase, new features and bugfixes submitted to any of the projects are
 **eligible** to be shipped as part of the next release. No changeset submitted
 during this period is however guaranteed to be merged for the current release
 cycle.
 
 ## The freeze period
 
 Six weeks after the beginning of the cycle, the codebase is officially frozen
 and the codebase reaches a state close to the final release. A Release Candidate
 (RC) gets created at the same time. The freeze period is used to find bugs and
 get feedback on the state of the RC before the release.
 
 During this freeze period, while the `master` branch will continue its normal
 development cycle, no new features are accepted into the RC. As bugs are fixed
 in `master` the release owner will selectively 'cherry-pick' critical ones to
 be included into the RC. As the RC changes, new ones are made available for the
 community to test and review.
 
 This period lasts for three weeks.
 
 ## How to maximize chances of being merged before the freeze date?
 
 First of all, there is never a guarantee that a specific changeset is going to
 be merged. However there are different actions to follow to maximize the chances
 for a changeset to be merged:
 
 - The team gives priority to review the PRs aligned with the Roadmap (usually
 defined by a ROADMAP.md file at the root of the repository).
 - The earlier a PR is opened, the more time the maintainers have to review. For
 example, if a PR is opened the day before the freeze date, it’s very unlikely
 that it will be merged for the release.
 - Constant communication with the maintainers (mailing-list, IRC, Github issues,
 etc.) allows to get early feedback on the design before getting into the
 implementation, which usually reduces the time needed to discuss a changeset.
 - If the code is commented, fully tested and by extension follows every single
 rules defined by the [CONTRIBUTING guide](
 https://github.com/docker/docker/blob/master/CONTRIBUTING.md), this will help
 the maintainers by speeding up the review.
 
 ## The release
 
 At the end of the freeze (nine weeks after the start of the cycle), all the
 projects are released together.
 
 ```
                                         Codebase              Release
 Start of                                is frozen             (end of the
 the Cycle                               (7th week)            9th week)
 +---------------------------------------+---------------------+
 |                                       |                     |
 |           Development phase           |    Freeze phase     |
 |                                       |                     |
 +---------------------------------------+---------------------+
                    6 weeks                      3 weeks
 <---------------------------------------><-------------------->
 ```
 
 ## Exceptions
 
 If a critical issue is found at the end of the freeze period and more time is
 needed to address it, the release will be pushed back. When a release gets
 pushed back, the next release cycle gets delayed as well.