Each z/OS Open Source Language and Tool comes with some manner of open source license. Most, but not all, are licensed under GPL, the GNU General Public License. The license document for each distribution can be found in this location:
If you need to read the license for a particular language or tool without downloading and unpacking it, then you must go to the public community pages for that language or tool. The license document included with our distributions is (by law) identical to the license you will find in the public pages.
Rocket adds the following additional terms and conditions in the following README file which can be found at the root level of the distribution.
Rocket Ported Tools for z/OS ("Program")
See more detailed information in directory
NOTICES AND INFORMATION
To the extent that a Rocket ported tool is subject to the GNU General Public
License (GPL) or other open source license that requires source code
distribution, Rocket provides human-readable source code available for
download from the Rocket Software Community Portal.