It's maintained, minor changes as late as January 2023 (https://www.itl.nist.gov/div898/handbook/changes.htm https://www.itl.nist.gov/div898/handbook/changes.ht

It's maintained, minor changes as late as January 2023 (https://www.itl.nist.gov/div898/handbook/changes.htm https://www.itl.nist.gov/div898/handbook/changes.htm). This is stable stuff! The retro html needs a bit of a refresh, but everything seems to work AFAIK.