The article describes the features of a library automation application called Micro CDS/ISIS. The software produced by UNESCO is used by more than 15,000 institutions all over the world. It is free of cost and is readily available. Its technical features include minimum hardware requirements, large database capacity, variable length fields, repeatable fields, subfields, powerful indexing, and rapid searching. It follows international data exchange standards. Support features include extensive documentation and a worldwide user group. Training courses in CDS/ISIS are conducted throughout the world. Because of these characteristics, CDS/ISIS may be recommended as the best library software for developing countries.