machinekit-hal is a split out repo which just contains the HAL elements of machinekit
It can be built as a RIP and used in the same way as a machinekit RIP, but without the CNC elements.
Install machinekit-hal-{flavour} if using packages.
NB. There is a related repo machinekit-cnc, which contains all the CNC elements missing from this repo. This can be built as a combined RIP build with machinekit-hal, by invoking scripts/build_with_cnc from the root of the machinekit-hal clone.