Trivia time! The windows console host (conhost) provides the “UI” for nano server. Even on desktop Windows, it’s built with support for running without a windo

Trivia time! The windows console host (conhost) provides the “UI” for nano server. Even on desktop Windows, it’s built with support for running without a window manager. The rendering engine is named “wddmcon” and it lives in our repository at [1]; it’s pretty much the most barebones console renderer we have. Reverse video and most color support were obviously[2] never implemented… even though I would have liked to spend engineering effort on it. The decision predates me, but I suspect it’s because they weren’t necessary for local validation. Wddmcon eventually evolved into the rendering engine used in Windows Terminal[3]; it’s still not very good[4], but it works in conhost as well. Eventually, we can bring those changes or whatever future rendering engine we write back to wddmcon. It has a sister renderer, “bgfxcon”. Bgfxcon renders text to the blue screen/boot graphics driver in the event that WDDM is unavailable. If you manage to open multiple (full-screen) console sessions, you can flip between them using Alt-Tab. This service is provided by the “console I/O server”, a CSRSS component available only on Nano Server that mimics some of the user32 things conhost needs, such as keyboard input. It also handles brokering us a WDDM or BGFX handle on startup. Unfortunately, that one’s closed-source… not because it should be, but because disentangling the build process for a component that lives in CSRSS wasn’t on our critical path. [1]: https://github.com/microsoft/terminal/tree/main/src/renderer/wddmcon https://github.com/microsoft/terminal/tree/main/src/renderer... [2]: which the article has already called out! [3]: https://github.com/microsoft/terminal/tree/main/src/renderer/dx https://github.com/microsoft/terminal/tree/main/src/renderer... [4]: https://github.com/microsoft/terminal/issues/10362 https://github.com/microsoft/terminal/issues/10362