My understanding is that both font and editor must support it; the editor must know when/how to render the ligatures, but the font must define what the glyphs l

My understanding is that both font and editor must support it; the editor must know when/how to render the ligatures, but the font must define what the glyphs look like, or else they won’t look any different that the regular sequence of characters. I’m far from an expert, though; I’ve just gotten so used to having ligatures over the past few years that I now find it uncomfortable not to have them.