IBM® Compiler and Library for REXX™ on zSeries® are a high-level language compiler and runtime library.
This combination of compiler and library facilitates your REXX scripting and System z application development and runtime.
Alternate Library for REXX on zSeries
The Alternate Library for REXX on zSeries enables users who do not have the Library for REXX on zSeries installed to run compiled REXX programs. It contains a language processor that transforms the compiled programs and runs them with the REXX interpreter, which is shipped as part of the OS/390, z/OS, and z/VM operating systems.
Software developers can distribute the Alternate Library, free of charge, with their compiled REXX programs. This allows customers who have the REXX Library installed to gain the performance benefits of running the compiled REXX programs, and also allows customers who don't have the REXX Library to still run the programs (as interpreted).
By including the Alternate Library in their program packages, software developers gain the benefits of shipping compiled REXX programs without the source code:
- Maintenance of the program is simplified since the code can not be modified inadvertantly.
- Compiled programs can be shipped in load module format, simplifying packaging and installation.
Note that when using the Alternate Library, the performance of compiled REXX programs is similar to that of interpreted programs. The performance benefits of compiled REXX are only available when the REXX Library is installed.
The Alternate Library for REXX on zSeries is included in the Library for REXX on zSeries program package. Software developers can then re-package the Alternate Library as part of their applications.