This paper reviews the experimental activities since 1979 for the study of the spin polarization of photoelectrons emitted by atoms and molecules exposed to VUV radiation. Two series of studies have been performed: First, using unpolarized and linearly polarized radiation the photoionization of the rare gases Ar, Kr, and Xe has been studied in an angle-, energy-, and spin-resolved photoemission experiment. Second, the spin polarization of photoelectrons produced by circularly polarized VUV radiation has been measured for some atoms and molecules. This was performed for most targets by use of the synchrotron radiation in Bonn.