Where I mention "Clipper" in this article, I am referring to the product published by Computer Associates and now formally known as "CA-Clipper." Clipper's 5.2c release is current as of this writing. Most of this article applies to both the 5.01a and 5.2c releases, except that the ITEM API and RDD specifications were not documented until after the 5.2b release. Also, with the 5.2 release, Clipper's developers have renamed the standard Extend API header file for C from EXTEND.H to EXTEND.API (although the EXTEND.H name has been grandfathered). Much of the Extend API itself has not changed since the Summer '87 release and can be used just as I show here.Clipper 5.2 also includes the ITEM API, which is a Clipper-sanctioned way to evaluate Clipper functions and code blocks from within C or assembler code. Available now is the Replaceable Database Driver API, which allows developers to write drop-in interfaces to other database engines.