EtherCalc

EtherCalc is a web spreadsheet for real-time collaborative editing. It is a TypeScript rewrite of a Node.js port of Multi-user SocialCalc, built to let people share a room URL and edit the same sheet together.

It runs on the Cloudflare stack with Hono, Workers, Durable Objects, D1, KV, and R2, and it also self-hosts anywhere with docker compose up. The command line path starts the app locally, and the Docker path keeps room state under ethercalc-data or /data in the container. A REST API exposes spreadsheet contents, and the app embeds in Drupal through sheetnode.

The current rewrite stores each room in Durable Object SQLite files. Anonymous read and write stays open to anyone who knows a room URL, so internet-facing instances pair it with a reverse proxy for TLS and rate limiting. Legacy Redis-backed installs can stay pinned to a pre-rewrite tag or migrate with a turnkey script. Tested in Safari, Chrome, and Firefox.