» For other uses of the term, see Fossil (disambiguation) FOSSIL is a standard for allowing serial communication for telecommunications programs under the DOS operating system. FOSSIL is an acronym for Fido Opus Seadog Standard Interface Layer. A "FOSSIL" driver is simply a communications device driver. They exist because in the early days of Fidonet, computer hardware was very diverse and there were no standards on how software was to communicate with the serial interface hardware. Initial dev… (More on Fossil)