The limiting factor to the exploitation of the huge photon flux produced by a third-generation synchrotron light source is very often the detector. Experiments in material science often exploit X-ray diffraction. A fast and efficient detection of diffraction patterns enables dynamic experiments. Monolithic active pixel sensors (MAPS) can be exploited effectively to build fast and efficient detectors for X-ray diffraction. For its material science beam lines Diamond Light Source is developing and evaluating detectors based on commercial MAPS and MAPS developed for scientific applications. The various projects, target performance and some experimental results are reported in this paper.