With the advent  of XMM-Newton and Chandra, it  has become possible to
map in detail  the dominant baryonic component in  groups and clusters
of  galaxies -  their  hot, X-ray  emitting  gas. This  is enabling  a
picture to be  pieced together of the complex  evolutionary history of
the  baryons in  these systems,  and of  the relationship  between the
galaxies and  their surrounding hot  gas. I will discuss  some ongoing
efforts  to map  the  processes driving  baryonic  evolution on  these
scales,  with   particular  emphasis   on  the  most   commont  galaxy
environment in the nearby Universe, small groups of galaxies.