Principles of Protein Structure '96 - Index to course material. Snow Crystals - Information about the physics of snow crystals and snowflakes as well as the history of early scientific observations and photographs, how to take photos, preserving snow crystals, and unusual snowflakes. Introduction to Cubic Crystal Lattices - A site introducing the properties of crystals with a cubic unit cell. SDPD Internet Course - Commercial e-learning course teaching how to determine a crystal structure from powder diffraction data. Xtal-protocols - Manual with information about (membrane) protein crystallization for X-ray crystallography. Kevin Cowtan's Picture Book of Fourier Transforms - For future crystallographers. Crystallography 101 - An Introductory Course by Bernhard Rupp. Interactive Tutorial about Diffraction - A pictorial guide to using these techniques especially for working out structural information, largely through the use of illustrative examples. Moving Crystallographic Instruction into the Digital Age - Educational module for use by researchers, teachers and students, provided by Kent Ratajeski, University of West Georgia.