I was trying to find the latest version of Notepad++ for Windows 98, and came across a few threads threads claiming (incorrectly) that Notepad++ 5.9.1 would work. Well, it's sort of correct, but only the ANSI version of 5.9.1 works on Windows 98, and that's not available anywhere as far as I can see.

So, I figured I'd try the latest version of Notepad++ 4.x and hey presto, Notepad++ 4.9.2 works great on Windows 98!

Download: http://www.oldversion.com/windows/notepad-4-9-2