ShadowLight is a virtual reality application that provides an immersive environment for multipurpose design and evaluation. Unlike traditional design tools that provide a built-in set of manipulators keyed to a particular set of design tasks, or evaluative systems that provide limited manipulation capabilities, ShadowLight offers a loosely defined environment that is capable of supporting the unique needs of both audiences. ShadowLight provides an atmosphere that is flexible enough to support rapid prototyping and design tasks, while at the same time permitting a richness of extensibility that allows scientific and industrial tasks to be performed using the same environment. ShadowLight defines only a basic interface that is extended through the development of plugins. The collection of plugins that is loaded at any given moment defines the capabilities available, and hence what the application “becomes” to its user. ShadowLight specifically seeks to address the current state-of-the-art in which several different environments must be employed for design, evaluation, and exploration tasks. In their place, ShadowLight attempts to provide a single environment that can be selectively extended to address the unique needs of a particular application field.