ProtoChart is a new opensource library using Prototype and Canvas to create good looking charts. This library is highly motivated by Flot, Flotr and PlotKit libraries. Features

• Line, bar, pie, curve, mix, and area charts available
• Multiple data series on same graph
• Highly customizable legend support
• Customizable grid, grid border, background
• Customizable axis-tick values (both x and y)
• Supports: IE6/7, FF2/3 and Safari
• Even works on an iPhone!

You can check out examples of using ProtoChart by exploring the left menu.

For a complete overview please visit: http://deensoft.com/lab/protochart/