math lib for .NET. n-dim arrays, complex numbers, linear algebra, FFT, sorting, cells- and logical arrays as well as 3D plotting classes help developing algorithms on every platform supporting .NET. Sources from SVN, binaries: http://ilnumerics.net
FusionCharts Free is a flash charting component for web applications, desktop applications and presentations. It livens up your boring data by converting it to animated and interactive charts.