The QuickTest software implements the statistical methods for uncertain (imputed) genotype association testing that were published in the article Methods for testing association between uncertain genotypes and quantitative traits in Biostatistics. The v0.95 executable, source code, documentation and example files can be requested at the official software page, but can also be directly downloaded from here.
The code was originally written by Toby Johnson and Zoltán Kutalik in 2009. The Vital-IT computational resource was provided by the Swiss Institute of Bioinformatics. Additional code was added by Alisa Manning and Han Chen at Boston University.
The latest - alpha - version of Quicktest features multivariate SNP association testing and can be downloaded from here. Note that it is not a stable version.