From the X-PLOR Manual:
X-PLOR is a system for computational structural biology. X-PLOR stands for exploration of conformational space of macromolecules restrained to regions allowed by combinations of empirical energy functions and experimental data. It also stands for exploration of modern concepts of structured programming in macromolecular simulation. X-PLOR's main focus is the three-dimensional structure determination of macromolecules using crystallographic diffraction or nuclear magnetic resonance (NMR) data. The program is based on an energy function approach: arbitrary combinations of empirical, geometric and effective energy terms describing experimental data may be used. The combined energy function can be minimized by a variety of gradient descent, simulated annealing, and conformational search procedures. The first version of X-PLOR (1.0) was published in the fall of 1987; it had evolved from a modified CRAY version of the CHARMM program (Brooks et al. 1983). X-PLOR was the first program to combine X-ray crystallographic diffraction data and molecular dynamics for refinement (Bringer, Kuriyan, and Karplus 1987). Since then the program has undergone extensive development, and the focus has shifted from refinement to structure determination. Major features of computational X-ray crystallography and solution NMR-spectroscopy have been included. Future development of X-PLOR is aimed at providing a comprehensive system for all computational aspects of macromolecular structure determination. X-PLOR is more than a program: it is a macromolecular language. This flexible language allows the user to experiment with new ideas without being restricted to standard or ``hard-wired" protocols. X-PLOR was designed to provide user friendliness, machine portability, and highly efficient algorithms for modern computers.
To run this software interactively in a Linux environment run the commands:
module add xplor xplor