A forerunner of the ATLAS was first published in 1970(1). This early survey comprised 27 zeolite structures known at the time. Then the "Atlas of Zeolite Structure Types" by W.M. Meier and D.H. Olson, with 38 entries, was published by the Structure Commission of the IZA in 1978. This was followed by the much expanded 2nd edition of the ATLAS in 1988 comprising 64 entries, the updated 3rd edition in 1992 with 85 entries, and the fully revised 4th edition in 1996 with 98 entries. This 5th edition is again an updated version of the previous compilation, and the number of entries has risen significantly to 133.