Robert (aka "Bob") Chassell was one of the founding directors of Free Software Foundation (FSF) in 1985. While on the Board of Directors, Chassell was also the treasurer for FSF. He left the FSF to become a full-time speaker on free software topics.
Chassell has authored several books including:
Chassell, Robert J. (2003). Software Freedom: An Introduction. Boston: GNUpress. ISBN1-882114-95-7.
Chassell, Robert J. (2004). An introduction to Programming in Emacs Lisp. Boston: GNUpress. ISBN1-882114-56-6.