Adopted an orphaned open-source project that was still widely used in the genomics community, despite no updates in ~4 years. Used SIMD instructions, careful memory management, and other strategies to speed up most operations by 1-4 orders of magnitude and support the current generation of biobank-scale genome-wide association studies (https://academic.oup.com/gigascience/article/4/1/s13742-015-... ).