I wrote a GUI toolkit from scratch — window creation, message loop, GPU

rendering, widgets, layout, text and IME, all in one static library. No Qt,

no SDL, no GLFW.

Then I counted the lines. 87,094. And wrote down where the time actually went.

What Zekit is

One static library. Downstream projects link a single file. No FreeType install, no Vulkan SDK, no third-party setup.

Hand-written window layers. Win32 and X11 directly. No SDL, no GLFW, no Qt.

Three render backends. D3D12, Vulkan and OpenGL on Windows; OpenGL (EGL) and Vulkan on Linux. All of them consume the same display list, so the same UI looks the same everywhere.

Value-semantic widget tree. Widgets are stack locals. win.AddWidget(btn) hands them over; no new , no delete .

Real IME. IMM32 integration, composition drawn in place, candidate window following the caret.

The four things that actually cost time

1.…