The recent development of intense positron beams is discussed. In addition to projects for intense positron beams based on the utilization of high energy electron linear accelerators in USA, Japan, China and Germany, efforts have been made to use nuclear research reactors to produce intense beams. Recently, an intense beam named POSH has been completed at the Delft research reactor. Other reactor beams are under development in Germany and in the US. Issues of common interest such as source configuration, extraction of slow positrons and transport and focusing of positrons are discussed. One of the applications of intense sources is aimed at better resolving the momentum distributions for thin films and interfaces in 2D-ACAR systems coupled to intense beams. Since March 2000 the POSH beam is in use for depth selective 2D-ACAR studies on ion implanted and layered structures.