The GHC developers are very pleased to announce the availability of the
third release candidate of GHC 9.14.1. Binary distributions, source
distributions, and documentation are available at [downloads.haskell.org][].

The changes from the second release candidate are:

- Fix RTS segfaults in certain situations (#26495)
- Fix use after free on windows due to a linker optimisation introduced in an 
earlier RC (#26613)

GHC 9.14 will bring a number of new features and improvements, including:

* Significant improvements in specialisation:
   * The `SPECIALISE` pragma now allows use of type application syntax
   * The `SPECIALISE` pragma can be used to specialise for expression arguments
     as well as type arguments.
   * Specialisation is now considerably more reliable in the presence of
     `newtype`s

* Significant GHCi improvements including:
  * Correctness and performance improvements in the bytecode interpreter
  * Features in the GHCi debugger
  * Support for multiple home units in GHCi

* Implementation of the [Explicit Level Imports proposal][levels]

* `RequiredTypeArguments` can now be used in more contexts

* SSE/AVX2 support in the x86 native code generator backend
* A major update of the Windows toolchain and improved compatibility with
  macOS Tahoe

* ... and many more

A full accounting of changes can be found in the [release notes][]. Given the
many specialisation improvements and their potential for regression, we would
very much appreciate testing and performance characterisation on downstream
workloads.

Note that while this release makes many improvements in the specialisation
optimisation, polymorphic specialisation will remain disabled by default in the
final release due to concern over regressions of the sort identified in
[#26329][T26329]. Users needing more aggressive specialisation can explicitly
enable this feature with the `-fpolymorphic-specialisation` flag. Depending
upon our experience with 9.14.1, we may enable this feature by default in a
later minor release.

GHC development is sponsored by:

 * [Juspay](https://juspay.com/)
 * [QBayLogic](https://qbaylogic.com/)
 * [Channable](https://www.channable.com/)
 * [Haskell Foundation](https://haskell.foundation/)
 * [Serokell](https://serokell.io/)
 * [Well-Typed](https://well-typed.com/)
 * [Tweag](https://www.tweag.io/)
 * [Dotcom-Monitor](https://www.dotcom-monitor.com/)
 * [LoadView](https://www.loadview-testing.com/)
 * [Web Hosting Buddy](https://webhostingbuddy.com/)
 * [Find My Electric](https://www.findmyelectric.com/)
 * [Standard Chartered](https://www.sc.com)
 * [UpCloud](https://upcloud.com)

We would like to that these sponsors and other anonymous contributors
whose on-going financial and in-kind support has facilitated GHC maintenance
and release management over the years. Finally, this release would not have
been possible without the hundreds of open-source contributors whose work
comprise this release.

As always, do give this release a try and open a [ticket][] if you see
anything amiss.


[downloads.haskell.org]: https://downloads.haskell.org/ghc/9.14.1-rc3
[release notes]: 
https://downloads.haskell.org/ghc/9.14.1-rc3/docs/users_guide/9.14.1-notes.html
[ticket]: https://gitlab.haskell.org/ghc/homepage/-/issues/new
[macos]: https://gitlab.haskell.org/ghc/ghc/-/issues/26166
[T26329]: https://gitlab.haskell.org/ghc/ghc/-/issues/26329
[levels]: 
https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0682-explicit-level-imports.rst

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