Single photon avalanche diode arrays have achieved extraordinary performance and are beginning to replace vacuum tube photomultipliers in almost every application. While silicon based single photon avalanche diode arrays are a rapidly maturing technology, similar arrays in compound semiconductors have met with only limited success. This is partly due to the intrinsic high defect densities in compound semiconductors and partly due to the immaturity of the fabrication techniques available. Newly developed planar processing technologies hold the potential to substantially improve the performance of compound semiconductor SPAD arrays, including decreasing dark count rates, increasing single photon detection efficiencies, and increasing dynamic range. These new techniques have been applied to GaInP SPAD arrays, enabling the SPAD array pitch to be decreased to five microns and 40,000 SPADs/mm. The performance characteristics of these GaInP SPAD arrays will be described.