ZedGraph is a set of classes, written in C#, for creating 2D line and bar graphs of arbitrary datasets. The classes provide a high degree of flexibility - almost every aspect of the graph can be user-modified. At the same time, usage of the classes is kept simple by providing default values for all of the graph attributes. The classes include code for choosing appropriate scale ranges and step sizes based on the range of data values being plotted.
ZedGraph also includes a UserControl interface, allowing drag and drop editing within the Visual Studio forms editor, plus access from other languages such as C++ and VB.
Example charts generated with ZedGraph