This paper summarizes the breakthrough in III - V multiwafer MOVPE mass production applications using the Planetary Multiwafer Reactor with Gas Foil Rotation (5 X 3 inch/7 X 2 inch or 5 X 4 inch/8 X 3 inch) which was originally developed and patented by LEP for growth of GaAs/AlGaAs heterostructures and has been used successfully since then for HEMT production, laser fabrication, and GaInP deposition. In similar planetary reactors, GaAs and InP based materials for a wide range of optoelectronic applications have been produced. The use of low pressures is not only advantageous for the handling of P- containing compounds and reduction of overall gas consumption, but also allows drastic reduction of the amount of H2 required for driving the wafer support. The variation of thickness in these multiwafer systems is reduced to the order of 1 - 2% for GaAs, AlGaAs, GaInP, InP, GaInAs, and GaInAsP (1.55, 1.3, 1.05 micrometers ). Thus, one major advantage in comparison to MBE is that these reactors are capable of handling both GaAs and InP based processes with high concentration of phosphorus. For production of visible lasers (AlGaInP), GaInP HBTs, or complex solar cell structures, these processes have also been developed. This finally makes this MOVPE technology by far superior for production application than MBE.