Existing spallation neutron source upgrades, planned spallation neutron sources, and high‐energy accelerators for particle physics place demanding requirements on the H−sources. These requirements ask for increased beam currents and duty factor (df) while generally maintaining state‐of‐the art H−source emittance. A variety of H−sources are being developed to address these challenges. These include volume sources with and without the addition of cesium for enhanced H−production, increased df cesiated H−Penning and magnetron sources, and cesiated surface converter H−sources. Research on surface films of tantalum metal for enhanced volume H−production is also being studied. Innovative plasma production techniques to address the longer df requirement without sacrificing H−source reliability and lifetime will be reviewed. The physical bases, the goals, and perceived challenges will be discussed. © 2003 American Institute of Physics