Ordinate

Ordinate is a plain-text spreadsheet format and an app for working with it. It started with small personal tasks, such as tracking a dog's health records and organizing records for tax season. Markdown tables lack formula support, and full spreadsheet apps can feel excessive for these uses.

Its compact, readable syntax lets AI read and edit a workbook directly, without spreadsheet-specific tools. The desktop version includes an in-app agent that you can try with ChatGPT sign-in. Ordinate is open source.