Version scheme

The Qubes OS Project uses the semantic versioning standard. Version numbers are written as <major>.<minor>.<patch>. When <patch> is omitted (e.g., 4.1), it is usually either because <patch> is zero (as in 4.1.0) or because we are referring to a specific minor release irrespective of any particular patch release within it. Similarly, the major release number alone (e.g., R4) is sometimes used to refer to an entire release series inclusive of all minor and patch releases within it.

In general, patch releases are for backward-compatible bug fixes, minor releases are for backward-compatible enhancements and new features, and major release are for any backward-incompatible changes. This means that, in general, one should not try to introduce features or enhancements in patch releases or any backward-incompatible changes in patch or minor releases. (Templates are a notable exception, as upstream OSes almost always have their own release schedules.) Bug fixes are allowed in all releases, and backward-compatible changes are allowed in all major and minor releases.

Qubes OS minor releases generally include new features, new templates, and occasionally new defaults, but they are still backward-compatible in the sense that qubes and features that worked in the previous release still function, though the UI may be different in some cases. In general, deprecated features are removed only in major releases, and in-place upgrades between major versions are not guaranteed.

Following standard practice, version refers to any build that has been assigned a version name or number, e.g., 3.2-rc2, 4.0.4, 4.1-beta1. By contrast, release refers to any version that is intended for consumption by the general userbase. For example, 4.0.4 was both a version and a release, since it was stable and intended for general public use, while 4.1-beta1 was a version but not a release, since it was not stable and was intended only for testing. All releases are versions, but not all versions are releases.

The letter R, as in R4.1, stands for release. The abbreviation RC, as in 3.2-rc2, stands for release candidate.

Qubes distributions and products

We intend to make it easy to make a remix of Qubes, targeting another hypervisor or isolation provider. We may also create commercial products intended for specific circumstances. There is one distinguished distribution called Qubes OS. All source code for it is available for download under a free and open-source license and is openly developed on GitHub and our mailing lists. The rest of this document discusses Qubes OS. Another remix may have its own version series.

Release versioning

Qubes OS as a whole is released from time to time. When preparing a new release, we decide on the <major>.<minor> numbers (e.g., 3.0, which is short for 3.0.0). We then publish the first release candidate, e.g., 3.0.0-rc1. When we feel that enough progress has been made, we’ll release 3.0.0-rc2 and so on. All these versions (which are not yet releases) are considered unstable and are not intended for production use. You are welcome to help us test these versions.

When enough progress has been made, we announce the first stable release, e.g. 3.0.0. This is not only a version but an actual release. It is considered stable, and we commit to supporting it according to our support schedule. Core components are branched at this moment, and bug fixes are backported from the master branch. Please see help, support, mailing lists, and forum for places to ask questions about stable releases. No major features or interface incompatibilities are to be included in this release. We release bug fixes as patch releases (3.0.1, 3.0.2, and so on), while backward-compatible enhancements and new features are introduced in the next minor release (e.g., 3.1). Any backward-incompatible changes are introduced in the next major release (e.g., 4.0).

Please see issue tracking for information about how releases are handled in the issue tracker.

Release schedule

There is no specific schedule for releases other than a general roadmap. When the time comes, we declare a feature freeze, tag -rc1, and release an ISO. From this point on, no new features are accepted, and our schedule begins.

Each release candidate period is as follows: For the first two weeks, we accept and assign bug reports to be fixed before the next release candidate. For the next two weeks, we generally focus on fixing assigned bug reports, so issues discovered during this period may be postponed until a later RC. Finally, there is a one week current-testing freeze, during which time no new packages are released, in the hope that they will be installed and tested by wider user base.

The next RC is released five weeks after the former. All packages are published in the current repository, and the cycle starts over. There should always be at least one release candidate before the final release.

Stage Duration
initial testing two weeks
bug fixing two weeks
current-testing freeze one week

Starting with the second cycle (that is, after -rc1), two weeks into the cycle (after the primary bug-reporting period), we decide whether there should be another RC. If, based on the bugs that have been reported, we decide that the latest RC will be designated as the stable release, then we decide on its release date, which should be no more than one week later.

Release cycle

Bug priorities

When deciding whether the current release candidate is the final one, the Committee takes bug priorities into consideration. The meaning of them is as follows:

  • blocker — when any such bug is present in the current release candidate, it can’t be considered final release. Bugs with this priority must be fixed before the next release candidate, even if that means delaying its release (which should be considered only last resort option).

  • critical — when any such bug is present in the current release candidate, it can’t be considered final release. But such bugs are not qualified to delay next release candidate release.

  • major — existence of such bugs do not strictly prevent the current release candidate be considered final (but of course we should try hard to not have them there). Fixing bugs of this priority can be delayed and qualified as updates to the final stable release.

  • default and minor — existence of such bugs do not prevent the current release candidate be considered final. Fixing such bugs can be delayed to the next Qubes OS release. Eventually such fixes might be backported as an update to the stable release(s). (default should really be assigned a more specific priority, but in practice there are too many issues and not enough time, so default ends up staying on many issues.)

All above is about bugs, no features should be assigned to the current release after first -rc. Supreme Committee is free to adjust priorities appropriately.

Component version

Qubes release is defined as specific versions of components, which are developed more or less separately. Their versions are composed of major and minor version of target Qubes OS release followed by third component which is just incremented. There is no apparent indication that given version is stable or not.

There are some non-essential components like qubes-apps-* that are shared between releases. Their versions indicate oldest qubes-release that is supported. We try hard to support multiple releases by one branch to ease code maintenance.

Different Qubes releases remixes may comprise of different components and version are not guaranteed to be monotonic between releases. We may decide that for newer release some component should be downgraded. There is no guarantee that arbitrary combination of different versions of random components will yield usable (or even install-able) compilation.

Git tags and branches

We mark each component version in the repository by tag containing v<version>. Likewise, each Qubes OS release is marked by R<release> tag.

At the release of some release we create branches named like release2. Only bug fixes and compatible improvements are backported to these branches. These branches should compile. All new development is done in master branch. This branch is totally unsupported and may not even compile depending on maintainer of repository.

All version and release tags should be made and signed by someone from ITL staff. Public keys are included in qubes-builder and available at

Check installed version

If you want to know which version you are running, for example to report an issue, you can either check in the Qubes Manager menu under About > Qubes OS or in the file /etc/qubes-release in dom0. For the latter you can use a command like cat /etc/qubes-release in a dom0 terminal.