Excerpt from Professional SQL Server 2005 Reporting Services
The charting capabilities in SQL Server Reporting Services are quite impressive and as easy to use as those in Excel or Access, and, in many ways, they are more powerful. The charting components are based on Dundas Charts, developed by Dundas Software. Dundas provides a suite of ASP.NET charting components that have been available for .NET developers for several years. A chart item is based on a data set just like any data range and can use groups, query parameters, and filters in much the same way as a table, list, or matrix.
