Powerful HTML5 Graph Library: RGraph
RGraph is a free graph library that uses the HTML5 canvas tag.
Using the library, it is possible to create a wide variety of graph types:
- bar, pie, donut, gantt, radar, funnel, bi-polar charts
- line and scatter graphs
- LED display
- progress bar
The charts are interactive (respond to mouse-overs and clicks) and, optionally, they can load with animations or zoom to a specific point.
There is also an annotation feature where you can draw over the graphs for highlighting them.
P.S. RGraph is only free for personal use.