A comprehensive experimental study is described whose fundamental objective is to obtain CFD validation-quality measurements of turbulent, compressible mixing layers on a highly spatially resolved basis. A wide range of convective Mach numbers has been considered, varying from roughly Mc = 0.2 – 0.9, or essentially incompressible to highly compressible conditions. Schlieren and Mie scattering flow visualizations and axial static pressure measurements are used to establish neutral pressure gradient conditions along the mixing layer in each case. The boundary and initial conditions for each shear layer are documented, particularly the incoming boundary layers and freestreams on the four tunnel centerplane walls approaching the splitter-plate tip. Stereo PIV (SPIV) measurements in each mixing layer are of primary importance, including all three components of the mean velocity, the full Reynolds stress tensor, and higher-order moments. Care has been taken to clearly establish that fully-developed, self-similar conditions are reached for each mixing layer in the far field. In addition, the uncertainties for the critical SPIV measurements have been considered in detail. The website address is given at which all results of the current study are available for each case, including the test-section geometry, boundary and initial conditions, all flow visualizations, pressure and velocity measurements, as well as associated experimental uncertainties.