CASCADE is a Monte Carlo incorating the
CCFM small
x gluon evolution applicable to e-p, gamma-p and ppbar scattering. It
is
the only program which can simultaneaously describe small x processes
at
HERA, like forward jets, and also heavy quark production at HERA and at
the TEVATRON and the LHC.
RAPGAP is a full Monte Carlo suited to
describe Deep
Inelastic Scattering, inclusively and also diffractive DIS. At present
it is THE Monte Carlo describing best the data obtained in DIS at HERA,
including diffractive scattering.