Welcome to the EazyLink Popdown utility
The EazyLink popdown is run on the Z88, and is the server part which listens to commands sent to it from the serial port. The client part is run on a desktop operating system like Windows and functions as the window to the filing systems of both computers.
It exists as two versions. By default it is part of OZ 4.2 and newer, but has also a life of its own, so users running older roms can install it on an application card.
Here's a screen shot of EazyLink running on the Z88:
