Poincake: An Infinite Notes Canvas Built on the Poincaré Disk

A developer has released Poincake, a browser-based note-taking tool that abandons the standard flat plane in favor of the Poincaré disk model of hyperbolic geometry. Notes placed near the center appear at normal scale, while those pushed outward shrink toward an infinitely receding boundary, giving users effectively unbounded canvas space without the panning fatigue of conventional infinite whiteboards.

The choice of a non-Euclidean projection is more than a gimmick: hyperbolic space grows exponentially with radius, so a fixed-size viewport can hold an arbitrarily large semantic neighborhood. This makes the model a natural fit for sprawling, loosely connected thought graphs where related ideas stay visually close while distant context fades smoothly into the periphery.

The Show HN post invites feedback on the interaction model, performance, and whether the spatial metaphor actually helps users think — questions that hyperbolic UIs have raised since early experiments at Xerox PARC but rarely answered in a shipped consumer tool.