MIT gave X away and it became the standard way to draw on Unix

Each workstation maker had its own closed graphics system, so a Unix program could not display on another vendor's machine.

At MIT's Project Athena, Bob Scheifler and Jim Gettys built a window system that separated the client application from the display across the network.

MIT released it under a permissive license and settled on the X11 protocol, so vendors and academic projects alike could use it freely.

Make the display protocol open and network-transparent

Network transparency let a program on one machine display on another.

The permissive MIT license meant vendors and developers could adopt it freely.

A defined X11 version gave every vendor one concrete target to implement.

Backing it with a neutral X Consortium kept it out of any single company's control.

A protocol that is open and treats the display as a network resource becomes the common layer for every environment.

X11 became the standard graphical layer for Unix and Linux for decades and the MIT/X11 license spread widely; the X.Org Foundation still maintains the reference implementation.