Which display server is considered the old standard for Linux environments?

X11, also known as X Window System, is considered the old standard for display servers in Linux environments. It has been around since the mid-1980s and has served as the foundation for graphical user interfaces across various Unix-like operating systems, including numerous Linux distributions.

X11 allows for the separation of the display from the application processes, enabling remote display capabilities and flexibility in managing graphical outputs. Its architecture supports network transparency, allowing applications to run on one machine while displaying their interfaces on another, a feature that many users and developers have relied on for years.

Despite the introduction of newer display servers like Wayland and Mir, X11 remains prevalent in many systems due to its compatibility and extensive support from a wide range of applications and window managers. The ongoing use and advancement of X11 in certain environments demonstrate its importance in the history and evolution of graphical interfaces on Linux.