VX/FMS supplies all features of the original openVMS system. Supported features include, but are not limited to:
Double-wide, double-high characters
VX/FMS supports all VT-terminals (VT100 or higher) and DECwindow’s DECterm. VX/FMS is a fully functional implementation of OpenVMS FMS and can be run as a stand-alone product. For programs that take full advantage of VMS, VX/FMS is designed to be fully integrated with VX/RT
— Sector7’s VMS run-time support libraries for Linux/UNIX.