Bernard A. Galler was an American mathematician and computer scientist at the University of Michigan who was involved in the development of large-scale operating systems and computer languages including the MAD programming language and the Michigan Terminal System operating system.

MAD is a programming language and compiler for the IBM 704 and later the IBM 709, IBM 7090, IBM 7040, UNIVAC 1107, UNIVAC 1108, Philco 210-211, and eventually IBM System/370 mainframe computers. Developed in 1959 at the University of Michigan by Bernard Galler, Bruce Arden and Robert M. Graham, MAD is a variant of the ALGOL language. It was widely used to teach programming at colleges and universities during the 1960s and played a minor role in the development of Compatible Time-Sharing System (CTSS), Multics, and the Michigan Terminal System computer operating systems. The original version of the chatbot ELIZA was written in MAD-SLIP.