Attempts to develop high temperature superconductor (HTS) microelectro
nics have been limited by the immature nature of HTS circuit technolog
y. Much of the present effort worldwide is based on superconductor-nor
mal-superconductor (SNS) Josephson junctions (JJ's). Only within the p
ast three years have SNS junctions been fabricated which can be interp
reted with conventional proximity effect theory. We discuss the histor
y and present status of HTS SNS devices and the prospects for producin
g a mature technology for practical applications.