Introduction

Improv is a cross-platform multidimensional spreadsheet written in Rust, in the line of Lotus Improv and Quantrix. It separates three things a traditional grid tangles together:

• Structure: the named dimensions of a model (categories and their items).
• Logic: formulas over dimensions, not cell addresses.
• Data: the raw input values.

You model in named categories, items and measures instead of A1 cell coordinates:

Revenue = Price * Quantity
Total   = SUM(Revenue OVER Time)

Derived values flow through a differential-dataflow graph, so recalculation is always incremental: an edit propagates only to the cells it actually affects.

One model, many ways in

The same model opens in a NeXTSTEP-style desktop GUI, a terminal UI, a scriptable CLI, a streaming pipe, a JSON HTTP server, and inside Postgres, where pg_improv keeps results current as your tables change and LANGUAGE improv turns a formula into a SQL function. A model is a single store file, or lives in a Postgres database. Ways to Use Improv says which to reach for and when.

Status

Version 0.10.0 builds and passes its tests on Linux, macOS and Windows; the Postgres extension supports Postgres 15 to 18. External functions in Python, R, Julia or Pure run under a bubblewrap sandbox on Linux; WebAssembly functions run in-process with fuel and memory limits. On other systems they are refused unless the operator sets IMPROV_EXTFN_ALLOW_UNSANDBOXED=1. The GUI has no Save As, Open or Print yet, and the Postgres connection has no TLS (use a loopback port or an SSH tunnel). See the changelog for what changed in each release.

Reading order

1. Ways to Use Improv: pick a front end.
2. The Improv Model: categories, items, measures, coordinates.
3. Getting Started: build a model from the CLI.
4. The Formula Language: dimension-aware formulas and aggregation.
5. The Desktop GUI and Improv in Postgres.
6. Architecture & Design and Storage & Persistence: how it works inside.