Type rendering: font outlines and file formats
Tim Brown, writing for Typekit:
Miguel Sousa from Adobe recently explained in detail the benefits of PS-based outlines over TT-based outlines. At the most basic level, the difference between these two outline formats is a matter of mathematics (cubic vs. quadratic Bézier curves). But a font’s existence as one kind of outline or another can affect its file format, and not all web browsers support all file formats.