The Alternate Terminal Manager (ATM) is a separate runtime which you can install and use independently from the regular ACUCOBOL-GT graphical runtime. ATM runs only on Windows NT/Windows 2000. It is very similar to the regular UNIX or Extended DOS character-based runtimes, with one of the differences being that the ATM runtime can detect Acu4GL DLLs (and other DLLs). The ATM runtime comes with all the libraries it needs, compiled with different flags for the regular graphical runtime than for the character runtime.
This self-contained architecture of ATM allows you to use a Windows NT server machine in a way similar to UNIX machines. You can telnet to the Windows NT server (with a third-party telnet service) and execute a COBOL program in that telnet window. Note, however, that this does not allow you to run the runtime from a Console window on the Windows NT machine.
All major runtime functionality is available with the ATM runtime, keeping in mind that this is strictly a character-based program, so certain windows-specific features, such as pop-up dialog boxes and such, are not included.