Horizon Haskell has made Nix builds for the http://flora.pm project more reliable and eased the task of updating dependencies for the maintainers, who are not trained in taking care of Nix setups.

The Flora team does not need to interact with the Nix setup during most of the development cycle, which allows us to focus on product development.

The reactivity and reliability of the Horizon team has made it a clear choice for our needs, and we greatly appreciate each interaction with them.

Théophile Choutri — Project lead for the Flora package index project.

horizon-advance lets me test my code against upstream versions of GHC and dependencies before those land in any stable channels. This way I can keep my code forward-compatible to prevent any future breakages, and fix any breakages with confidence.

Tom Sydney Kerchove - Author of feedback, smos and sydtest.