HaLVM is a hypervisor-like operating system consisting of the GHC language runtime running on Xen.
Definition:
According to the Official Documentation:
What is the HaLVM?
The Haskell Lightweight Virtual Machine, or HaLVM, is a port of the Glasgow Haskell Compiler toolsuite to enable developers to write high-level, lightweight virtual machines that can run directly on the Xen hypervisor.
While Galois initially designed the HaLVM to allow for quick and easy prototyping of operating systems components, the HaLVM has grown over time to allow for a much wider variety of use cases. When connected with the appropriate libraries, the HaLVM can, for example, operate as a network appliance.
Writing for the Haskell Lightweight Virtual Machine is just like writing normal Haskell, and many pure Haskell libraries port to the HaLVM with little or no difficulty. In fact, we include the standard Haskell Cabal toolset in order to more easily facilitate the integration of outside Haskell libraries. However, instead of running on top of a typical operating system, HaLVM programs run at a very low level, directly on the Xen hypervisor. This allows for very lightweight, single purpose Xen domains with minimal resource requirements.
