The 3D Smith Chart program is a new Java tool for visualizing and designing active and passive microwave circuits. It generalizes the traditional 2D Smith chart onto the surface of a sphere, addressing limitations of the 2D chart. Key features include reading measurement files, plotting reflection coefficients for complex impedances, and aiding oscillator and amplifier design by visualizing infinite mismatch and stability circles. The tool aims to provide a complete graphical solution for microwave circuit measurement and design.