Silverlight 4: Chart Control

Is there a free chart control for silverlight 4 except for toolkit?

There are a number of charting components for Silverlight, some of the most popular free ones are the following:

• Visiblox - free version supports basic chart types, zooming, trackball and some other behaviours, comes with a watermark though. The documentation is decent. Good choice if you need performant charts or are planning on building on top of them. See examples using this component.
• AmCharts QuickCharts - a set of basic charts. Documentation is pretty basic. Good choice if you need the most basic charts. See examples using this component.
• Visifire - lots of chart types supported and they have a nice chart designer. Documentation is also decent. Good choice for a wide range of charting applications. See examples using this component. Update: since I've written this, Visifire have went to having only trial. Thus probably worth being a bit vary of them in terms of licensing.

Full Disclosure: I have been heavily involved in development of Visiblox, hence I know that library in much more detail than the others.