Experimental data on generation of negative hydrogen ions on cesiated molybdenum surfaces are presented. The following processes are discussed: backscattering of protons and H2+ions, sputtering of adsorbed hydrogen by cesium ion bombardment, and backscattering of a thermal or superthermal distribution of hydrogen atoms. The data are compared with theoretical calculations. Surface production is an important process in most negative hydrogen ion sources. An example of a negative hydrogen ion gun using hyperthermal hydrogen atoms incident on an external converter is presented.