MSI InsightII (aka Biosym) is used for the simulation of large molecular/biopolymer systems.
Insight II is a comprehensive graphic molecular modeling program. In conjunction with the molecular mechanics/dynamics program such as Discover, or CHARMm you can use the Insight II program to build and manipulate virtually any class of molecule or molecular system. In conjunction with other MSI products, you can study molecular properties.
See more indepth information here: Insight II