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Not even poor Notepad is safe from Microsoft's AI obsession
(www.theregister.com)
This is a most excellent place for technology news and articles.
Yeah, vim also has it today, but I don't know how far back that goes. Screen splitting, too, I use that all the time in vim and GUI editors.
We didn't have color terminals at my college so if there was any highlighting I wouldn't have seen it. Probably shortly after the first dumb terminals came with color text somebody made emacs or vi do highlighting? Screen splitting goes way back. Emacs had that in the late 80s when I was using it.