Shared world · October 2026 Live
Deriva
A shared island that changes over time and with the gestures of its visitors: water, plants, herbivores and predators following a few simple rules.
What it is
Every visitor sees the same world. The clock moves one simulated day every twenty real minutes; water sustains the plants, herbivores wear down paths and predators follow their prey. There’s no win condition: you can step in or just watch.
Each browser gets up to three gestures a day —rain, seeds, animals or fire— and the shared notebook records what happened, with a daily postcard of the island. At chick.cl/laboratorio, everyone also gets an island of their own to experiment with.
What I built
- A deterministic simulation on a 48 × 48 grid with 30-day seasons
- The shared island runs on a Worker with a D1 database: the server catches up on elapsed time when a visit arrives, with no always-on process
- Three gestures per browser per day, with a shared cap of 24 and no accounts or personal data
- A paginated notebook, downloadable daily postcards and “What happened here” to read the story of any spot
- A personal lab with pause, speed, layers, a restore point and worlds saved as JSON
The hard parts
One world for everyone
Progress is deterministic and computed whenever a visit arrives, in chunks of up to 24 steps: the island stays alive without a server running.
Gestures without accounts
A signed random cookie identifies the browser; on top of the per-person limit, a shared cap protects the island from anyone who clears their cookies.