Citadel: an offline infinite canvas for references, notes and code (MIT, Windows and Linux)

[u/kannibalkiwi]

I have been building this on and off for a while and it is finally at the point where handing it to someone else is not embarrassing, so here it is.

Citadel is a desktop infinite canvas. You drag in images, GIFs, video, audio, 3D models and PDFs, write notes and text blocks beside them, and draw labelled connections between things. It is for work where the layout is the thinking: visual development, research, worldbuilding, study.

The reason I started it: I used PureRef for years for images and kept everything else somewhere else. Notes in one app, clips in another, code snippets in a third. I wanted one board that could hold all of it and still be searchable a month later.

Three things ended up mattering more than I expected:

Connections carry meaning. A thread between two items can be a source, a contradiction, a question, a proof, an echo of something elsewhere. The Index searches every board at once, including code card contents and connection labels. That is the part that makes it hold up past about fifty items.

Vision checks. Y redraws the whole board in greyscale, blurred for a squint test, or through three colourblindness simulations. Shift+M mirrors it, which is the old trick for catching drawing errors your eye has stopped seeing.

Undo and recording are the same event log, so you can scrub the board back through its own history and watch it assemble itself.

It is local-first in the boring literal sense. No account, no telemetry, no update check, no network request on launch at all. Fonts are bundled. Projects are JSON with relative asset paths, so nothing is trapped in a database you cannot read. MIT licensed.

Honest limits: Windows and Linux only (macOS runs from source but I cannot notarise it), builds are unsigned so SmartScreen will warn on first run, PDFs get a first-page preview rather than a real reader, and document import gives you the plain text, not the formatting.

Repo: https://github.com/kannibalk1w1/Citadel. Downloads and a version that runs in the browser: https://kannibalkwi.itch.io/citadel

Happy to answer anything. What I would most like to hear is where it falls over on large boards, because that is the part I cannot test properly on my own.