Week 2: The Stack Beneath the Skin

Week 2, X11 versus Wayland, the role of the compositor, and what you are actually theming when you theme a desktop

1 March 2027

Before you can theme a desktop you have to know what a desktop is made of. Most of what a beginner calls “the desktop” is in fact several programs that have agreed to cooperate: a display server, a compositor, a window manager, a bar, a launcher, a terminal, and the applications on top. Change one and the others may stop cooperating. This lecture takes the stack apart so that later, when a tutorial says “just add this line”, you know which program you are talking to.

The central split is X11 against Wayland. X11 is old, permissive, and endlessly scriptable, which is why so much ricing tooling assumes it. Wayland is newer, stricter, and folds the compositor and display server together, which changes what is even possible to theme. Neither is a moral choice, whatever the forums tell you. They are different contracts, and the rest of your setup lives inside whichever one you sign.

In this lecture#

• display server, compositor, and window manager: who does what
• X11 and Wayland as two different contracts, not two teams
• what “theming” actually reaches: which layer owns your borders, gaps, shadows
• why a screenshot cannot tell you which stack produced it

Before next week#

Identify the stack on the machine you brought last week. Name every layer, and find the one program you will spend the most time fighting.