BILOGMG is used for the analysis of dichotomous data and can fit 1PL, 2PL and 3PL models. It can also be used for multiple group analysis, allowing the user to study DIF and DRIFT.

PARSCALE is a program for the analysis and scoring of rating-scale data. It can be used to perform multiple-group and DIF analysis. 

AUXAL Fast, comprehensive analysis of data from longitudinal growth studies with an improved Windows interface.