X2Go offers graphical app access to a remote Linux system. It is a simpler alternative to X11 redirection or VNC over SSH. X2Go supports disconnecting and resuming remote sessions.

X2Go Website

Note: These instructions assume that the x2goserver and xfce4-terminal have been installed on the remote host.

Installing X2Go

macOS

First download and install XQuartz

Download and install the X2Go Client for macOS

Windows

Download and install the X2Go Client for Windows

Linux

Most Linux distributions offer a X2Go client package. 

Ubuntu: apt-get install x2goclient

Red Hat derivatives: yum install x2goclient (Note: need to enable EPEL repo)

Create X2Go Session

Start X2Go Session

Click on the session name to start the session. It will prompt for your logon name and password.

Disconnect and Leave Session Running

Quitting X2Go client will leave the leave the remote session running. Reconnecting will reopen the running session.

macOS: Select "Quit x2goclient" from the x2goclient menu

Windows: Select Quit under the Session menu

Exit and End Session

End the session by exiting all apps running in the session and logout the session terminal windows.