The multigrid workbench project is an ongoing effort to design an interactive environment for multigrid algorithms. Central components are a graphical user interface and visualization modules. The workbench in its present form is based on a specialized high level toolset that provides the basic multigrid components for two-dimensional stationary diffusion equations. Because of its functional and stream-oriented programming style the workbench can be used to solve large systems with up to several million unknowns on standard workstations. This report discusses the related software engineering and efficiency issues. A prototype of the interactive user environment and basic visualization components is available.