1. See hardware abstraction layer.
2. In the 1968 book and movie “2001: A Space Odyssey” by novelist Arthur C. Clarke, the intelligent but eventually psychotic computer, HAL 9000, that takes over a spaceship bound for Jupiter. The name HAL is an acronym for Heuristic/ALgorithmic computer, but the letters H-A-L are also one letter removed from I-B-M in the alphabet.