In October of 2010 at Apple’s “Back to the Mac” event, Apple announced the then-latest version of its desktop operating system, Mac OS X Lion (version 10.7), which was released nine months later in July 2011. It sold one million copies on its first day, and over six million copies afterwards. In it, Apple unveiled new versions of Calendar, Mail, and Address Book apps. But there was one microinteraction that garnered a lot of attention, mostly because Apple deemed it unnecessary and removed it. That microinteraction? Save As.
In the early 1980s, Save used to be Save and Put Away (Xerox Star), or Save and Continue alongside Save and Put Away (Apple Lisa). (Put Away meaning close.) Save and Continue eventually just became Save, while Save and Put Away vanished, probably once more RAM allowed for multiple documents to be open at the same time without processor issues. Save As seems to have begun in the 1980s as Save a Copy as, which let users save a version as a new file without renaming. Eventually some applications had all three: Save, Save As, and Save a Copy as. Over time, as people understood the Save As paradigm, and with the broad adoption of the Undo command, Save a Copy as has mostly vanished.
At the time Apple decided to get rid of Save As, the rules of the microinteraction had been fairly stable for about 30 years:
Make changes to a file.
Save the file with a new ...