The metal-oxide-semiconductor field-effect transistor (MOSFET) is finding widespread application as a technology for memory systems, due both to advantageous device and technology characteristics, and to the unique requirements of the memory environment. The technology has proven quite versatile, and among the applications are random access systems, shift registers, and read-only storage. Both complementary and noncomplementary technologies have been used. The background and philosophy of using MOSFETs as a memory technology are reviewed, and the recent developments, trends, and the current state of the art are summarized. © 1970, IEEE. All rights reserved.