PLINK is a popular and computationally efficient software program that offers a comprehensive and well-documented set of automated genome wide association quality control and analysis tools. It is a freely available open source software written in C++, which can be installed on Windows, Mac and Unix machines. The focus of PLINK is purely on analysis of genotype/phenotype data, so there is no support for steps prior to this (e.g. study design and planning, generating genotype or CNV calls from raw data). Through integration with gPLINK and Haploview, there is some support for the subsequent visualization, annotation and storage of results. Registration not required.