In addition to Enterprise repositories, Varnish Software builds and maintains packages for popular Linux distributions.
Packages are hosted on packagecloud.io/varnishcache and while all previous packages are kept there, only four series are actively supported, as presented below.
As a rule of thumb, support for new distributions are introduced in the
weeklies and are generally not backported to other series.
Packages are generated every night by circleci, and every week (barring any veto from the team), one set of these is pushed to packagecloud.io. Needless to say those packages are geared towards enthusiasts wanting to try the new unreleased features and shouldn’t not be carelessly run in production.
The open-source sees biannual releases, generally around March 15th and September 15th. Following each release, a new packagecloud.io repository is created and populated.
Whether a release is a major or a minor is decided during the freeze period preceding the release.
Each release is supported (and so can see bug and security fixes) for a year after being released, meaning that at any given time, there are always two fresh versions that are supported.
For users requiring a slower upgrade model, the LTS version is a series that keeps being supported with bug and security fixes past the usual one-year deadline. The current LTS is 6.0.