We're using Haskell to create the world's first VR Linux Distro: https://github.com/SimulaVR/Simula

The long-term goal is to run Linux on standalone VR headsets. Right now we have something working with the HTC Vive.

The Window Manager is being written in Haskell (with lots of C/C++ FFI). It's a very serious project, attempting to do something with Haskell that isn't merely useful for more programming.