Nucleosynthesis at very low metallicities. Sketch of various nucleosynthesis and potential r-process sources within the early galactic interstellar medium, when only a few of such events have occurred. New star formation sites, inheriting the local interstellar medium composition, which is polluted to varying degrees by the remnant sites, are displayed as yellow stars. The figure also takes into account that neutron stars, produced in CCSN explosions, are in many cases kicked out of their supernova remnants (see also our Fig. 23).