OpenType, which extends TrueType with cubic curves and the typographic machinery that makes real typesetting possible - ligatures, alternates, small caps, proper kerning. Where a typeface has ambitions, it usually ships as OTF.

Every conversion below runs in this page, on your own machine. Nothing is uploaded, there is no queue, and there is no account to make. Pick a target format, or just drop an OTF file above and choose afterwards.