Protovis

Protovis composes custom views of data with simple marks such as bars and dots. Unlike low-level graphics libraries that quickly become tedious for visualization, Protovis defines marks through dynamic properties that encode data, allowing inheritance, scales and layouts to simplify construction. Supported chart types are area, bar, column, scatter, pie, donut, line, stacked, grouped, force-directed, streamgraphs and parallel coordinates charts.