Omasheet

What Markdown is to text, Omasheet is to numbers.

📄 Text as the source of truth

The spreadsheet becomes a readable, diffable and composable document, not just a binary workbook.

📊 Columns as the computational model

Named, typed data and array expressions connect spreadsheet authoring to dataframe-style transformations.

🔢 Exact arithmetic as a semantic guarantee

Numeric values retain their exact decimal or rational meaning instead of floating-point approximations.

The app automatically follows system dark/light mode.

const TaxRate = 20%

sheet Sales

| Month | Revenue | Cost | Profit | Tax | Running |
| ----- | ------- | ---- | ------ | --- | ------- |
| Jan   | 10000   | 6000 | *      | *   | *       |
| Feb   | 12000   | 7000 | *      | *   | *       |
| Mar   | 15000   | 8000 | *      | *   | *       |

Profit  := Revenue - Cost
Tax     := Profit * TaxRate
Running := [Revenue; 0..*].sum()

An .omx file is plain text: constants, functions and sheets, in any order. A line that starts with # is a comment. Formulas are written once per column and apply down every row, so a sheet reads like a small, typed program over its own data.

See Getting Started to install and run Omasheet, and the Guide for the file format, expressions, the app & CLI, and import/export.