The scientific literature in chemistry and physics abounds with abbreviations of chemical compounds, physical methods and mathematical procedures. Unfortunately, many authors take it for granted that the reader knows the meaning of an abbreviation, something quite trivial for a specialist. For the less informed reader, these abbreviations thus present definite communication problems. The Gmelin Institute of Inorganic Chemistry of the Max Planck Society has collected more than 4000 abbreviations for methods and terms from chemistry, physics and mathematics and more than 4000 chemical compounds (mostly ligands in coordination chemistry and standard reagents for physical and analytical methods). GABCOM and GABMET provide an overview enabling readers and authors to check the definition of an abbreviation used by an author and to see whether this abbreviation is already being used for other purposes. GABCOM and GABMET are also in preparation in electronic form (data file and search software) for IBM-PC or compatible computers.