NIST and other government institutes are not known for open source work mainly because most of their work is a combination of science and technology communication. They deal in publications, conferences, and reference datasets. In my industry, NIST and the NIH produce the most important R&D reference datasets in the world, and everyone else looks to them for guidance. With that said, the NIH also occasionally produces world class software too (NCBI BLAST, etc.) although they do have some issues with parts of their software engineering culture being a bit out of date.