FlexiMine --A flexible platform for KDD research and application development. FlexiMine is a KDD system designed as a testbed for data-mining research, as well as a generic knowledge discovery tool for varied database domains. Flexibility is achieved by an open-ended design for extensibility, thus enabling integration of existing data-mining algorithms, new locally developed algorithms, and utility functions such as visualization and preprocessing. Support for new databases is simple and clean: the system interfaces with a standard database server via SQL queries and thus can handle any application database. With a view of serving remote, as well as local, users, internet availability was a design goal. By implementing the system in Java, minor modifications allow us to run the user-end of the system either as a Java applications or (with some limitations on the user) as a Java Applet. This paper reviews the architecture, design and operation of FlexiMine and presents some of the new ideas incorporated in the data-mining algorithms (Association rules, Decision trees, Bayesian knowledge-bases and Meta-queries).