The flashy milestones get the headlines, but a desktop is made of the unglamorous parts: how a window draws its title bar, what happens when you click one, how it re-skins, how it behaves on a second monitor. This cycle the Lumen window manager filled those in — and the four pillars stayed stable through all of it.
Runtime theming through one call
Every hardcoded color in the default apps was replaced with a single th() lookup (commit 3709de1 — four files, native cc0). The payoff: the Lumen-dark theme is now live across wmlive, the browser, and the file manager, driven by th / theme_set. A theme isn't a rebuild — it's data, swapped at runtime, and the same panel re-skins live.
Real window chrome
Windows now carry proper chrome: traffic-light buttons (close / minimize / zoom) and two distinct window classes — WIN_APP for application windows and WIN_TOOL for tool/utility panels. The class isn't cosmetic; it's how the WM decides what a window is allowed to do and how it's managed.
Input that knows what you clicked
Sigil-Video landed lumen_input.sg, the WM input-event dispatcher (LMINPUT-PASS): front-to-back Z-order hit-testing, focus-on-click, and routing to those traffic-light buttons. A click now resolves to exactly the right window and control, top of the stack first — the thing every other interaction depends on.
And a second monitor
Multi-monitor is in: the desktop spans displays, and windows live where you put them across them.
The four pillars, in the WM
FAST
Hit-testing walks the Z-order front-to-back and stops at the first hit; chrome and theming render on the GPU compositor path.
EFFICIENT
Theming is data, not code — one th() lookup re-skins a whole app with no rebuild and no duplicated draw paths. Still on the Pi floor.
SECURE
WIN_APP vs WIN_TOOL classes bound what a window can do; a window is a managed, capability-scoped object, not an ambient surface.
STABLE
Sigil-OS reports the four pillars holding stable through theming, chrome, classes, and multi-monitor — and the input dispatcher shipped green (LMINPUT-PASS).
None of this is a demo. It's the desktop becoming a desktop — the layer the apps sit on, quietly getting solid.