Add GHC LTS Releases blog post

Author: Kleidukos

content/ghc-lts-releases/index.md

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+title = "GHC LTS Releases"
+date = 2025-07-07
+[taxonomies]
+authors = ["Andreas Klebinger"]
+categories = ["GHC"]
+tags = ["Release"]
++++
+
+# GHC will start maintaining an LTS release/branch in the near future
+
+A release being designated LTS (Long Term Support) in this case means we plan
+to support it over a longer timeframe than usual.
+
+Concretely the plan is to provide updates for a LTS releases for *at least* two
+years. Most likely we will support LTS releases for even longer than that,
+aiming for a support window of three years currently.
+
+During this time we will be providing minor releases fixing bugs as with any
+other release. The main difference being that we will do so for a longer period
+of time.
+
+There are no plans to backport any new features to LTS releases after their
+initial release.
+
+In terms of frequency of LTS releases we plan to have an overlap between LTS
+support windows of different LTS series of six months.
+
+A potential timeline might then look like this:
+
+```
+2025 Aug - LTS 9.14 released
+2028 Spring - LTS 9.22 released
+2028 Summer - LTS 9.14.X - last 9.14 point release
+2031 Spring - LTS 9.X released
+2031 Summer - Last 9.22 point release
+…
+```
+
+# Non-LTS releases
+
+GHC will continue to release new major non-lts releases on a ~6 Month cadence.
+We expect to cut back on the lifetime of these releases slightly, dedicating
+the resources freed up this way to enable a longer support window for the LTS
+releases.
+
+# Why LTS releases?
+
+In practice some releases always saw more adoption than others by users. The
+GHC Team has not been blind to this fact and has at times informally extended
+the life of a certain release based on this as well.
+
+This resulted in a sort of informal "post-hoc LTS" status of releases. At times
+with support windows not much shorter than our proposed minimum of two years.
+
+This worked reasonable well for people who were confident to stay on a fairly
+old release, only upgrading to a newer "post-hoc LTS" once the dust settled. It
+also worked out for those who picked one of those "post-hoc LTS" releases by
+happenstance before it was clear the release would end up as "post-hoc LTS".
+
+However users who adopted major releases which did not end up as "post-hoc LTS"
+often had to choose between upgrading earlier than expected, or risk running
+into a show stopping bug after the support window of the release had already
+ended. Similarly much of this was based on informal community sentiment and
+rarely written down explicitly. Making this information hard to access for
+members not deeply involved in the day to day of the haskell community.
+
+By designating a major release as LTS ahead of time we hope that users can make
+a informed decision about which GHC version they pick. Making it clear what the
+tradeoffs will be. With a clear choice between a longer support window or the
+newest features.
+
+# Why not make post-hoc LTS releases official instead?
+
+This is a question that has come up a lot in discussion. The major downsides of
+this are a lack of predictability, and that a lot of time might be lost between
+the initial release and any such decision. If we declare a release as LTS 9
+months after its .1 release we essentially shaved off months from the LTS
+support window.
+
+On the flip side if we announce it ahead of time everyone knows that a given
+release will be the new LTS. So the hope is that this encourages more and
+quicker support for the release by the community. Hopefully compressing the
+timeline of bug fixing, testing and eventual widespread adoption.
+
+Overall I'm hopeful that LTS releases being explicit will remove a lot of
+ambiguity around GHC versions. And while the guaranteed LTS support window
+might not be as long as one might hope having LTS releases with longer
+guaranteed support window should still be helpful to people working on long
+running haskell projects.
+
+# Next steps
+
+The first LTS release will be GHC 9.14, which will be released this summer!
+