Products needed from ftp://fnkits.fnal.gov/

To run D0RunII
    ups
    upd
    perl
    python
    gtools v2_1
      pulls several others
    geant (monte carlo)
    cern

To build D0RunII
    msql  (d0omMSQL)

To use other parts of the code management system
    cvs

Many others available if you wish.