Features

Grid, formulas, formatting, charts, print/PDF, XLSX/CSV/ODS, encrypted .ycell.

Poll/SSE sources, sheet-as-source model, auto named ranges, time-travel, stats.

E2E-encrypted, per-sheet/range permissions, real-time, presence, gateway.

Signed WASM module hub; local JS/Python editors; signed publishing.

Local-first, self-deployable (NAS/Docker), no limits when self-hosted.

Technical details: the documentation.