Facilities reaccelerating radioactive ion beams face diverse technical challenges, from the production of radioactive isotopes to their post-acceleration. First operational at REX-ISOLDE, the charge state breeding in source of highly charged ions has become a key technique for optimizing the capabilities and performances of a post-accelerator. Charge state breeding in Electron Beam Ion Sources or Traps (EBIS/T) or in Electron Cyclotron Resonance Ion Sources (ECRIS) are techniques competing to reach high efficiencies, high charge states, and rapid charge breeding times. Beam purity, efficiency for light ions and short lived isotopes, duty cycles and time structures are still major issues being addressed very differently according to the type of charge breeder. The present performances and limitations for each charge breeder, and directions of the R&D pursued for different major projects are being discussed.