eXtended Compiler for REXX (XCR)
- Creates encræypted load modules. By improvIT Software Innovations GmbH.
- http://www.improvit-software-innovations.de/cms/content/view/43/57/

IBM Compiler and Library for REXX on zSeries
- Product description, library and news.
- http://www-306.ibm.com/software/awdtools/rexx/rexxzseries/

MAX Software
- MAX/REXX interfaces to DB2, VSAM, PDS and SAM data sets on OS/390. Also REXX extensions.
- http://www.maxsoftware.com/

RtoR - REXX to RACF
- Development tool kit for RACF (OS/390 Security Server) applications. Access the live RACF database.
- http://www.open-softech.com/rtor.htm

REXXTOOLS/MVS
- Access to data sets, DB2, APPC and TCP/IP on OS/390. By Open Software Technologies.
- http://www.open-softech.com/rexmvs.htm

Relational Architects International: Rexx Language eXtensions
- Interfaces for SQL, VSAM, DB2 commands, CAF services, IFI requests, ISPF, NetView. REXX SDK for OS/390 with system APIs and compiler.
- http://www.relarc.com/