The evolution and current operation of the Ontario Computer Assisted Instruction (CAI) Network are described. Sponsored by the Ontario Institute for Studies in Education and including 11 community colleges in Ontario, the network has computer installations and access devices throughout the province. Initial development work was done using a Digital Equipment Corporation (DEC) System 10 computer operated by the National Research Council. More recently, a Burroughs B-6700 has been brought into the network. Courseware development has taken place on the campuses of participating institutions and the primary programing languages have been FORTRAN, ALGOL, and CAN which is an intermediate level system control language for CAI. (DGC)