A software bus is a software architecture model where a shared communication channel facilitates connections and communication between software modules. This makes software buses conceptually similar to the bus term used in computer hardware for interconnecting pathways.[1]
In the early microcomputer era of the 1970s, Digital Research's operating system CP/M was often described as a software bus.[2][3] Lifeboat Associates, an early distributor of CP/M and later of MS-DOS software, had a whole product line named Software Bus.[4] D-Bus is used in many modern desktop environments to allow multiple processes to communicate with one another.
Further complications arose when Lifeboat Associates agreed to help promote MS-DOS but decided to call the operating system Software Bus 86. MS-DOS thus became one of a line of trademarked Software Bus products, another of which was a product called SB-80, Lifeboat's version of CP/M-80.