Zoyd

In 2002, when Apple introduced Audio Units (AU), Urs realised that nobody was offering a decent GUI construction kit for plug-ins. While others discussed the general AU feature set, he created a quick and easy GUI toolkit called CAUGui.
CAUGui allowed Urs to create the first AU with a fancy custom user interface—Rumblence:pure. An incredibly buggy distortion plug-in. He subsequently developed Zoyd, one of the first ever AU synths. Zoyd never really left the beta stage, but apparently some people still use it now and again.
Free!
