Zekton

Zekton is a good looking and modern font.

About X11:

In computing, the X Window System (commonly X11 or X) is a windowing system which implements the X display protocol and provides windowing on bitmap displays. It provides the standard toolkit and protocol with which to build graphical user interfaces (GUIs) on most Unix-like operating systems and OpenVMS, and has been ported to many other contemporary general purpose operating systems.

X provides the basic framework, or primitives, for building GUI environments: drawing and moving windows on the screen and interacting with a mouse and/or keyboard. X does not mandate the user interface - individual client programs handle this. As such, the visual styling of X-based environments varies greatly; different programs may present radically different interfaces. X is not an integral part of the operating system; instead, it is built as an additional application layer on top of the operating system kernel.

Unlike previous display protocols, X was specifically designed to be used over network connections rather than on an integral or attached display device. X features network transparency: the machine where an application program (the client application) runs can differ from the user's local machine (the display server).

X originated at MIT in 1984. The current protocol version, X11, appeared in September 1987. The X.Org Foundation leads the X project, with the current reference implementation, X.org Server, available as free software under the MIT License and similar permissive licences

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