A sprite based HTML5 potentiometer widget. Another little experiment of mine. I wanted to make a 'realistic, VST-like' looking pot knob for the web, so here it is.
By default, the knobs are controlled by rotating them, but you can specify an option (verticalDrag: true) with which you can enable vertical mouse click & drag control. When controlling the widget by vertically dragging the mouse, you can hold down the ctrl button (option on mac) to fine tune the value. You can also double-click and type in the value with the keyboard (check out demo2 for that).
You can find instructions and more info in the docs.
Example use cases: