Embedded toolchain and/or HAL/register map:

- Copilot (by NASA)

- MicroHs — for running Haskell on an MCU

GUI library and/or basic keyboard/mouse I/O:

- Monomer

- sdl2

- gi-gtk4

GPU interaction library

- OpenGL bindings

- vulkan bindnigs

- Accelerate — numerical GPU computation with an NVIDIA backend.

Web framework with database access, auth, users, routing, and templates:

- IHP

- Yesod

Pretty sure those all exist; e.g. at work we use Yesod and Servant, which are a couple of Haskell web frameworks.