IVEware

Missing data problems and variance estimation in complex surveys is a standing problem facing most large scale surveys. IVEware was developed by the Survey Methodology Program at the University of Michigan’s Survey Research Center, Institute for Social Research and is available to researchers without cost.
A SAS interfacing version(requiring SAS) and stand alone Windows and Linux versions are available.
Additional information is available at: http://www.isr.umich.edu/src/smp/ive/