@lcamtuflcamtuf
Early 70s, I was writing an A*-based program to lay out PCBs, and in that context called it the Manhattan distance. Used it as the minimum-remaining-cost estimate. (Hard to believe the things we did in 64KB.)
If you have a fediverse account, you can quote this note from your own instance. Search https://ioc.exchange/users/jlundell/statuses/115206210701593260 on your instance and quote it. (Note that quoting is not supported in Mastodon.)