Directory Opus (DOpus) is an impressive file manager program written by GPSoftware, in Australia. It replaces Windows Explorer and integrates lots of features, including file compression, FTP capabilities, folder syncing and much more.
Quick Access Popup is fully compatible with Directory Opus. It is fully aware of DOpus capabilities and utilizes them via the internal
DOpusRt.exe commands to offer seamless and reliable integration.
See:
How do I enable Directory Opus support in Quick Access Popup?
See also these two videos:
QAP and Directory Opus