  Collider detectors have taken advantage of the resolution and accuracy of
silicon detectors for at least four decades. Future colliders will need large
areas of silicon sensors for low mass trackers and sampling calorimetry.
Monolithic Active Pixel Sensors (MAPS), in which Si diodes and readout
circuitry are combined in the same pixels, and can be fabricated in some of
standard CMOS processes, are a promising technology for high-granularity and
light detectors. In this paper we review 1) the requirements on MAPS for
trackers and electromagnetic calorimeters (ECal) at future colliders
experiments, 2) the ongoing efforts towards dedicated MAPS for the Electron-Ion
Collider (EIC) at BNL, for which the EIC Silicon Consortium was already
instantiated, and 3) space-born applications for MeV $\gamma$-ray experiments
with MAPS based trackers (AstroPix).
