PDM
From MidrangeWiki
PDM is an object and source managment system included as part of OS400.
It is only available on a 5250 emulator. A next generation editor, beyond PDM, is Code/400. A previous generation editor before PDM, such as on S/36 SSP, was SEU which now is built inside of PDM.
From command line GO CMDPDM gets you a list of commands available to access PDM, such as editing programs, and other software objects.
See PDM 54