GCI is the Generic Call Interface for REXX interpreters. GCI allows REXX programmers access to all shared libraries (aka DLLs) where there are no REXX-specific wrappers.
Wrapper library for adding MySQL support into the REXX language. Libraries are written in C and then imported into REXX scripts. Once imported REXX scripts can access most of the functions of the MySQL C API through REXX.
Rexx/gd is a Rexx interface to the gd graphics library. This interface allows a Rexx programmer to create and manipulate graphics images.