The GT.M programmer can use any VMS editor to create M source files, including EVE, the EDT keypad emulator, or a custom Text Processing Utility (TPU) program. The GT.M ZEDIT command provides access to a VMS TPU program directly from M.
The GT.M programmer also uses the Direct Mode facility to interactively debug, modify, and execute M routines. In Direct Mode, GT.M executes each M command immediately, as if it had been in-line at the point where GT.M initiated Direct Mode.
The following is a list of additional enhancements available from the Direct Mode:
The capability to issue commands from Direct Mode to the VMS Command Language Interpreter (CLI), generally DCL
A command recall function to display and reuse previously entered commands, similar to the DCL recall function
Many language extensions that specifically optimize the debugging environment