X11
X Window System is a system for implementing a window-based user interface on bit-mapped displays. X11, the most current and widely used version of X, is designed to communicate all the information necessary to operate a window system over a single asynchronous bi-directional stream of 8-bit bytes. The X protocol specifies four types of messages but named extensions can also be defined to extend the system. X11 usually runs on TCP port 6000, 6001, 6002, etc.
Available to all SRX running 12.3X48+
Available to all MX running 20.2R1+
Available to all vSRX running 20.3R1+