REXX is IBM's dynamic scripting and extension language, developed by Mike Cowlishaw at IBM's UK Labs in 1979. It is descended from EXEC, the command language for IBM's CMS operating system, and influenced by PL/I. REXX is used extensively on IBM platforms, especially OS/2, and is now available for other platforms (e.g. DOS, Windows, UNIX). REXX is like Tcl in that it is simple and the string is its only data type. REXX is easily interpretable, and many is often implemented only as an interpreter, although compilers are available. Object REXX extends REXX with object-oriented semantics, by adding objects, classes, and methods to REXX's strings and functions. It also adds a number of predefined classes. Object REXX programs can interact with Smalltalk, C, or C++, programs via SOM (or DSOM, IBM's OMG CORBA-compatible extension to SOM, for distributed interaction). IBM is also developing a VisualAge-based GUI builder and visual application development environment for Object REXX. Object REXX is being used by NIIIP, a US-government sponsored consortium aimed at facilitating electronic commerce on the Internet. NetRexx is REXX's response to Java, a REXX to Java translator that permits REXX programs to be delivered as Java bytecodes, and executed on client platforms with the Java Virtual Machine, combining the ease and efficiency of REXX programming with the performance and wide availability of the Java VM.