Darren's Rexx Add-ons
RxSock and RxDial, including C source code. By Darren Abbott.
LesTec Pty Ltd
Modular And Integrated Design (MAID) for Windows and OS/2 (visual Rexx GUI) and input/output function library.
Lueck Data Systems - Solutions
Offers free ObjectCUR cross-platform utility library, including CUR for classic Rexx.
Rexx/CURL
Interface to the cURL package for access to URL-addressable resources such as web pages, ftp sites, and telnet sessions.
RexxTags
Rexx Server Pages compiler for rapid prototyping of XML tags in Rexx. Requires Apache and Mod_Rexx. [Open surce, Common Public License]