Other crystallography wikis

• CCP4 developers' wiki
• [1] - IUCr site with definition of terms and formulas
• http://www.zampbioworld.org/zampwiki/?t=X-ray_crystallography
• http://nanocrystallography.research.pdx.edu/search.py/index
• PDBWiki contains one wikipedia-style page per PDB entry where details about each structure can be discussed. Has a very useful PDB_FAQ.