Version 3.0 of the NIST/NASA/CARB Biological Macromolecule Crystallization Database (BMCD) includes crystal and crystallization data on all forms of biological macromolecules which have produced crystals suitable for X-ray diffraction studies. The data include summary information on each of the macromolecules, crystal data, crystallization conditions and comments about the crystallization procedure if it varies from the traditional methods employed for crystal growth. The database-management software maintains continuity with previous versions providing similar search procedures and displays. Version 3.0 of the BMCD includes protocols and results of crystallization experiments undertaken in space. These new data are comprised of both the NASA Protein Crystal Growth Archive, which includes information on all NASA-sponsored protein crystal growth experiments, and data describing other internationally sponsored microgravity macromolecule crystallization studies. The entries for the space growth crystallization experiments contain the crystallization protocols, apparatus descriptions, flight summary data, indication of success or failure of the experiments, references, etc. Other new features of the BMCD include the addition of crystallization procedures for small peptides and cross references to other structural biology databases.