Molecular beams form the technological basis for a wide range of chemical and physical studies. We report here an advance in producing cold beams of atoms and molecules with high intensity. This method is general in that it uses helium, an inert gas, to cool species, even refractory and radical molecules. Cold molecular oxygen and atomic ytterbium were produced with peak fluxes of 5X10^14 and 5X10^15 particles per second per steradian, respectively. This represents an improvement of about a factor of 1000 over all previous sources. This may find application in precision measurement and loading of mesoscopic microtraps for quantum information.