On Windows, 64-bit versions of 4D v16 can be opened multiple times.

Traditionally in older versions of 4D, to run multiple instances, multiple copies of the application is needed. This changes in v16 64-bit. Multiple copies of 4D is no longer needed. One 4D application can now open multiple instances of 4D by simply double clicking the 4D.exe for the amount of times as you want the amount of instances running.