  CMOS pixel sensors (CPS) represent a novel technological approach to building
charged particle detectors. CMOS processes allow to integrate a sensing volume
and readout electronics in a single silicon die allowing to build sensors with
a small pixel pitch ($\sim 20 \mu m$) and low material budget ($\sim 0.2-0.3\%
X_0$) per layer. These characteristics make CPS an attractive option for
vertexing and tracking systems of high energy physics experiments. Moreover,
thanks to the mass production industrial CMOS processes used for the
manufacturing of CPS the fabrication construction cost can be significantly
reduced in comparison to more standard semiconductor technologies. However, the
attainable performance level of the CPS in terms of radiation hardness and
readout speed is mostly determined by the fabrication parameters of the CMOS
processes available on the market rather than by the CPS intrinsic potential.
  The permanent evolution of commercial CMOS processes towards smaller feature
sizes and high resistivity epitaxial layers leads to the better radiation
hardness and allows the implementation of accelerated readout circuits. The
TowerJazz $0.18 \mu m$ CMOS process being one of the most relevant examples
recently became of interest for several future detector projects. The most
imminent of these project is an upgrade of the Inner Tracking System (ITS) of
the ALICE detector at LHC. It will be followed by the Micro-Vertex Detector
(MVD) of the CBM experiment at FAIR. Other experiments like ILD consider CPS as
one of the viable options for flavour tagging and tracking sub-systems.
