jFreeChart - Java and .NET chart library

jFreeChart is a widely used open source charting library. Its flexible design is easy to extend and targets both server-side and client-side applications. It supports many output types, including Swing components, image files (PNG and JPEG) and vector graphics file formats (including PDF, EPS and SVG).

It may not provide real time charts, updating the dataset once per second is fine. Refreshing the chart less than a second will result in high cpu load.

jFreeChart.NET - JFreeChart ported on .NET.

Demo: http://www.jfree.org/jfreechart/jfreechart-1.0.13-demo.jnlp