For visualizing his data, Militzer used Crumbs, a volume-rendering tool developed by Rachel Brady and her colleagues at NCSA. Although Crumbs has been around since 1994, it is growing in popularity as virtual reality (VR) environments are being installed at partner sites throughout the Alliance. Crumbs is one of the few software tools that helps new VR users get up and running quickly. Unlike other volume-rendering programs that are custom-coded for a particular dataset, Crumbs provides generic volume rendering tools that automatically display the data in VR. Militzer chose to customize Crumbs, though, by adding the electron paths, protons, and molecular bonds. Without this capability the visualization would have shown only the electron density. Programming in the capabilities required one week--time Militzer says was well spent. The Crumbs executable is available from the CAVERNUS website.