Rocketcharts, Open-source HTML5 Financial/Statistical Charts

blog.chasegale.com

Pretty nice. Another excellent charting library is highcharts, they also have released a stock charts library too.

Highcharts.com

The one thing I haven't found is a nice chart library that can do gantt charts properly, so if anyone knows of one let me know.

Haven't used the Gantt part personally, but Fusion supports it: