The dynamics of globular cluster systems

Kinematical data for globular clusters in early-type galaxies are taken with different 
objectives. One is the identification of subpopulations which in combination with other 
parameters like ages and metallicities may provide clues to the formation history of the 
globular cluster system.
Another one is the usage of globular clusters to  constrain the dark halos of their host 
galaxies, again in combination with other dynamical tracers. I shall  summarize what 
globular clusters have told us and what we can expect from the future.