The Alcatel SEL single-axis fiber-optic gyros are described. Application areas are identified and rationale is given for the use of fiber-optic gyros in the different market segments. The applications reach from retrofit of mechanical rate gyros to integrated navigation systems. The ongoing development and engineering effort is concentrating on multiple-axes solutions with reduced size and optimized manufacturing cost. The most promising subsystem is a tactical grade inertial measurement unit with a fiber-optic gyro triad as rotation rate sensors.