you are probably referring to user styles, aren't you? The extension here is called GreaseMeleon, though I'm not sure about the K-M versions it works in.
Userstyles and userscripts are completely different things, I don't know why you think the poster is conflating them. Also, the UserStyles extension is called Stylish
, not GreaseMeleon. GreaseMeleon is the K-Meleon version of GreaseMonkey (which is, indeed, the extension they would want if they were looking for UserScripts), and it doesn't work well in any KM version, AFAIK.