Spreadsheet GitHub Repositories (2026) · Open Source Tools

We're rebuilding and open-sourcing the world’s software from scratch.

Free, open-source AI Office suite: Docs, Sheets, Slides, PDF, Markdown and HTML editors with a built-in AI agent, plus a `genoffice` CLI and agent skill so Claude Code, Codex and Cursor can create and edit real .docx/.xlsx/.pptx files locally. Bring your own key. macOS, Windows & Linux.

Build your own AI office with Univer Office SDK. Bring editing, calculation, collaboration, and file processing into your product for people and AI agents. Built on an extensible open-source core.

Grist is the evolution of spreadsheets.

Go language library for reading and writing Microsoft Excel™ (XLAM / XLSM / XLSX / XLTM / XLTX) spreadsheets

SpreadCheetah is a high-performance .NET library for generating spreadsheet (Microsoft Excel XLSX) files.

A terminal spreadsheet multitool for discovering and arranging data

Main engine of the IronCalc ecosystem

A pure rust library for reading and writing spreadsheet files

Read and write spreadsheet files (CSV, XLSX and ODS), in a fast and scalable way

VTable is not just a high-performance multidimensional data analysis table, but also a grid artist that creates art between rows and columns.

Read and write Office Excel documents from Clojure

Simple excel-like datasheet Blazor component

Native OOXML engines in Rust - DOCX, XLSX & PPTX editing, rendering and real-time collaboration, compiled to WASM for the web.

NanoXLSX is a small .NET library written in C#, to create and read Microsoft Excel files in the XLSX format (Microsoft Excel 2007 or newer) in an easy and native way

View & edit DOCX, XLSX, PPTX in the browser. Progressive loading, formulas, real-time collab, saves to original format.

ODF generation library for Ruby

A pure PHP library for reading and writing spreadsheet files