[opensourcedex]

ibis-office is a free, open source office suites project written in Rust and released under AGPL-3.0. It has 525 GitHub stars, 29 forks and 48 open issues, and was last pushed 4 days ago. On this registry it ranks #20 of 20 tracked projects in Office Suites, with 5 head-to-head comparisons available.

What is ibis-office?

ibisOffice is an open-source office suite written entirely in Rust that views, edits and saves Word (.docx), Excel (.xlsx) and PowerPoint (.pptx) documents from one codebase running as a desktop application on Windows, macOS and Linux or in a WebGPU-capable browser, built for people who need Microsoft Office files to render the way Office renders them.

What it is

ibisOffice is an office suite whose interface and document rendering are drawn on the GPU, using DirectX, Metal, Vulkan and WebGPU, with the application logic written in memory-safe Rust on top of GPUI. The same single codebase ships as a native desktop app for macOS, Windows and Linux and as a WebAssembly build that runs in the browser, so a document opens the same way regardless of the platform underneath. It handles three formats in one application — documents, spreadsheets and presentations — and both opens and saves them, rather than acting as a read-only viewer.

The concrete problem it addresses is layout fidelity. A document authored in Microsoft Office should look the same when opened in ibisOffice, down to line breaks, page breaks, table borders and even chart tick marks, and every part of the renderer is built to reproduce Office's output. The second half of that problem is round-tripping: files must stay Microsoft Office files, so that a document opened and saved in ibisOffice can be reopened in Office with nothing in the content or the layout lost. It lives in the Rust and GPUI ecosystem and targets Microsoft Office as the specific product whose rendering and file behaviour it reproduces.

Key capabilities

  • One application for .docx, .xlsx and .pptx, with viewing, editing and saving for all three.
  • Word processing coverage that includes fields (page numbers, tables of contents, indices, cross-references), equations in OMML, LaTeX and UnicodeMath, track changes and comments, mail merge, content controls, document protection, vertical text, ruby and East Asian typography.
  • Format conversion from documents to .doc, .rtf, .odt, .html, .txt and .pdf.
  • A spreadsheet engine with over 500 worksheet functions, dynamic arrays and spilling, LET and LAMBDA, structured and 3D references, PivotTables and PivotCharts, slicers and timelines, and What-If Analysis covering Goal Seek, Data Tables, Scenario Manager, Forecast Sheet and Solver.
  • Charting that spans 2D and 3D plus Office 2016+ types such as Waterfall, Treemap, Sunburst, Histogram, Pareto, Box & Whisker and Funnel, alongside sparklines.
  • A command-line interface for headless batch conversion to PDF and PNG, print settings and performance benchmarking, documented in docs/cli-options.md.
  • An embeddable browser build with optional Close and Download buttons that hand the embedding page an event, documented in docs/web-embedding.md.

Who uses it and how

  • Desktop users on Windows 10 and 11 (64-bit), macOS 11 or later on Apple silicon, and Linux x86_64 with glibc 2.31 or later, where the AppImage runs without installation or FUSE.
  • Browser users who open the playground with a WebGPU-capable browser and try the sample Word, Excel and PowerPoint documents without installing anything.
  • Publishers and product teams that embed the browser version in their own pages and capture the Close and Download events.
  • Automation and batch workflows that call the CLI for headless PDF or PNG conversion, print settings and benchmarking.
  • Teams working on a shared document, which the server edition is intended to support with several people editing at the same time.

Getting started

Download the archive for the platform — ibisOffice-0.8.6-Windows.zip, ibisOffice-0.8.6-macOS.zip or ibisOffice-0.8.6-Linux.AppImage — unzip or chmod +x it as appropriate, and run it. Alternatively, open the playground at https://ibisjp.github.io/ibis-office/ in a browser with WebGPU to try it with no installation.

How it compares

The facts name no other open-source suite for comparison, so ibisOffice stands alone in this registry as its Office-suite entry; the reference point throughout is Microsoft Office itself. It is licensed AGPL-3.0 and runs natively on Linux and inside the browser, and its stated measure of success is matching Office's rendering of line breaks, page breaks, table borders and chart tick marks while keeping saved files openable in Office.

When to use it — and when not to

Choose it when layout fidelity to Microsoft Office, a native Linux build or an in-browser editor matters, and when an AGPL-3.0 copyleft licence fits your distribution policy. Skip it if you need an Intel Mac build, a non-x86_64 Linux target or a browser without WebGPU, since none of those are offered in the provided facts, and note that real-time collaboration depends on a server edition described only as a goal, with no installation method given. The README excerpt supplied here is also truncated mid-sentence in the spreadsheet section and gives no feature-level detail for .pptx beyond support, so that format is worth testing directly before committing.

project readme (upstream, from github) — read inline

English | 日本語 | 简体中文

The next-generation office suite, built with Rust and the GPU, that opens your documents exactly as Microsoft Office shows them.
Word (.docx), Excel (.xlsx) and PowerPoint (.pptx) — fast, accurate, everywhere.

What is ibisOffice?

ibisOffice is an office suite for viewing, editing and saving Word, Excel and PowerPoint documents. It is written entirely in Rust and draws everything on the GPU. The same single codebase runs as a desktop app on macOS, Windows and Linux and in the web browser.

Our aim is simple: a document made in Microsoft Office should look the same when you open it in ibisOffice. Line breaks, page breaks, table borders, even chart tick marks — we build every part to produce the same result as Office.

Get started

Download the desktop app


ibisOffice-0.8.6-Windows.zip
Windows 10 / 11 (64-bit)
ibisOffice-0.8.6-macOS.zip
macOS 11 or later (Apple silicon)
ibisOffice-0.8.6-Linux.AppImage
Linux x86_64

  • Windows: download and unzip ibisOffice-0.8.6-Windows.zip, then run ibisOffice.exe in the ibisOffice folder.

  • macOS: download and unzip ibisOffice-0.8.6-macOS.zip, then move ibisOffice.app to your Applications folder.

  • Linux: download ibisOffice-0.8.6-Linux.AppImage, allow it to run as a program (chmod +x), and double-click. Runs on major desktop Linux distributions (glibc 2.31 or later: Ubuntu, Debian, Fedora, Arch Linux, etc.). No installation or FUSE is needed.

  • Try the web version: open the playground in your browser — no installation (a browser with WebGPU). Open the sample Word, Excel and PowerPoint documents and try it right away.

  • Changelog: see CHANGELOG.md for release notes and recent updates.

  • Watch the video: an introduction to ibisOffice (YouTube).

    ibisOffice introduction video

  • Command-line interface: for batch headless conversion to PDF/PNG, print settings, and performance benchmarking, see Command-Line Options.

  • Embedding the browser version: optional Close and Download buttons that hand the embedding page an event, see Embedding.

Goals

ibisOffice aims to be a world-class open-source office suite.

  • Speed and robustness: memory-safe Rust code that opens large documents quickly and does not crash.
  • Looks the same as Microsoft Office: text positions, line breaks, page breaks, tables, charts and shapes drawn just as Office draws them.
  • Files that stay Microsoft Office files: open and save, then reopen in Office — nothing in the content or the layout is lost.
  • Any OS: the desktop app works and looks the same on macOS, Windows and Linux.
  • Native speed in the browser: with WebAssembly and WebGPU, no installation needed.
  • Real-time collaboration: with the server edition, several people edit the same document at the same time.

Features

Three formats, one app

  • Documents (.docx): paragraphs and styles, bullets and numbering, tables, columns, vertical text, ruby and East Asian typography, footnotes and endnotes, headers and footers, fields (page numbers, tables of contents, indices, cross-references), equations (OMML, LaTeX, UnicodeMath), shapes, images, charts, SmartArt, ink annotations, track changes and comments, mail merge, content controls, document protection, and format conversion (.doc, .rtf, .odt, .html, .txt, .pdf).
  • Spreadsheets (.xlsx): over 500 worksheet functions, dynamic arrays and spilling, LET and LAMBDA, structured and 3D references, conditional formatting (data bars, color scales, icon sets), number formats (including Japanese era and custom formats), rich text and phonetic guides (furigana) within cells, AutoFilter, multi-column sorting, tables, PivotTables and PivotCharts, slicers and timelines, 2D/3D and Office 2016+ charts (Waterfall, Treemap, Sunburst, Histogram, Pareto, Box & Whisker, Funnel), sparklines, form controls, ink annotations, data validation, Flash Fill, consolidation, subtotals, What-If Analysis (Goal Seek, Data Tables, Scenario Manager, Forecast Sheet, Solver), Power Query data tables, threaded comments and notes, sheet and workbook protection, and format conversion (.xls, .ods, .csv, .tsv, .txt, .html, .dif, .slk, .pdf).
  • Presentations (.pptx): slide masters, layouts, themes and variants, custom slide sizes, sections, headers and footers, speaker notes and handouts; shapes (all 187 ECMA-376 preset geometries, boolean merge operations, vertex editing, 3D rotation, bevel and extrusion), WordArt and text effects, equations, tables, charts, SmartArt, pictures (crop to shape, artistic effects, background removal), 3D models, video and audio (trim, fade, bookmarks, closed captions), ink annotations, action buttons and zoom links; animations (entrance, emphasis, exit, motion paths, triggers, chart/SmartArt build steps), slide transitions (including Morph and sound effects), slide shows and Presenter View (dual-display, teleprompter, laser and pen annotations), custom shows, rehearsal and recording preview, comments, presentation comparison, accessibility checker, password encryption, and format conversion/export (.ppt, .odp, .ppsx, .potx, .pdf, .png, animated .gif).
  • Macro-enabled files (.docm, .xlsm, .pptm) open and save too. Macros are never run; they are kept as they are.

Compatibility, measured — not eyeballed

We verify visual compatibility by measurement. For each feature we build test documents and compare, pixel by pixel, the PDF that real Word, Excel and PowerPoint produce with what ibisOffice draws. Files saved by ibisOffice are checked to open in Office without repair.

A fast screen, drawn on the GPU

The screen is drawn on the GPU (Metal on macOS, DirectX on Windows, Vulkan on Linux, WebGPU in the browser), so scrolling, zooming and switching sheets are smooth. The UI is built with GPUI, the UI framework created for the high-performance Zed editor.

Desktop and browser

The same Rust code runs as a native app and, as WebAssembly, inside the browser.

Strengths

  • A new implementation, written from scratch in Rust: no legacy code inherited from older office suites. Memory-safe, parallel and fast.
  • Rendering compatibility, guaranteed by process: more than 70,000 tests continuously compare ibisOffice with Office's output, pixel by pixel.
  • Every edit is a "command": every change goes through a command that carries only IDs and final values. It is the unit of undo and redo, and also the unit exchanged with the server in collaborative editing.
  • Faithful to the standard: files are read and written following the international standard for Office Open XML (ECMA-376 / ISO/IEC 29500 / JIS X 4191). Built-in definitions such as shape outlines use the official ECMA-376 data distributed by Ecma, unmodified.
  • Only components that are safe for commercial use: every library we depend on is under a license that allows commercial use, such as Apache-2.0, MIT or BSD. No copyleft libraries are used (checked on every change with cargo deny).

Motivation

We provide ibisStorage, a file storage and sharing service like Google Drive. It needs to preview and edit Office files online — fast, accurately, and without putting load on the server. That is why we are building ibisOffice.

Speed

Smaller is faster. The figures in parentheses show how many times longer each product took than ibisOffice.

From opening a file to the first screen

With the app already running, the time from telling it to open the file until the first page (the first slide for pptx, the first screen of the first sheet for xlsx) is fully displayed.

File ibisOffice Microsoft Office LibreOffice ONLYOFFICE
Presentation (.pptx)
31 slides, 35.9 MB		 0.59 s 2.16 s (3.7×) 4.40 s (7.5×) 4.75 s (8.1×)
Document (.docx)
140–154 pages in English, 0.12 MB		 0.45 s 1.11 s (2.5×) 1.70 s (3.8×) 3.15 s (7.0×)
Spreadsheet (.xlsx)
22 sheets, 29 charts, 589,000 formulas, 13.7 MB		 0.52 s 14.07 s (27.0×) 6.82 s (13.1×) 9.36 s (17.9×)

We recorded the app window (up to 60 frames per second) and measured, from the video, the time from the open request until the screen stopped changing. The final frame was checked by eye.

1,000,000-Row CSV: Time to First View

With the app already running, the time from telling it to open a 1,000,000-row CSV file until the first screen is displayed and interactive for viewing, scrolling, and zooming.

File ibisOffice LibreOffice Microsoft Excel ONLYOFFICE
Large CSV (.csv)
1,048,576 rows, 20 columns, 116 MB
(Time to First View)		 0.78 s 11.30 s (14.5×) 19.04 s (24.4×) 137.3 s* (176.0×)

* ONLYOFFICE failed to open the 1,000,000-row file (timed out after 5 minutes); estimated at 3.3× its 300,000-row load time (41.60 s).

Converting to PDF

The time from starting a command-line conversion until the PDF is fully written.

File ibisOffice Microsoft Office LibreOffice ONLYOFFICE
Presentation (.pptx)
31 slides, 35.9 MB		 1.42 s 8.40 s (5.9×) 32.26 s (22.8×) 5.87 s (4.1×)
Document (.docx)
140–154 pages in English, 0.12 MB		 0.69 s 12.49 s (18.1×) 3.45 s (5.0×) 4.19 s (6.1×)
Spreadsheet (.xlsx)
22 sheets, 29 charts, 589,000 formulas, 13.7 MB		 7.26 s 42.94 s (5.9×) 19.46 s (2.7×) 24.89 s (3.4×)

Conversion methods: ibisOffice ibisOffice --export pdf; Microsoft Office: opened and saved as PDF via AppleScript; LibreOffice soffice --headless --convert-to pdf; ONLYOFFICE: the x2t converter bundled with the app.

Test conditions

  • Environment: Apple M2 Pro, 16 GB memory, macOS 26.5.1. Versions: ibisOffice 0.1.0 (development build), Microsoft Office 16.113.2, LibreOffice 26.8.0.3, ONLYOFFICE 9.4.0. Measured on September 29–30, 2026.
  • Each figure is a single run. Every run started with all of the app's processes quit.
  • The files are made from fictional data and from a public document with its metadata removed, and are published in test/benchmark/.

Use cases

Desktop app (macOS, Windows, Linux)

  • Your everyday office software: create and edit Word, Excel and PowerPoint documents and save them in the same formats as Office.
  • Check documents you receive, instantly: open files from email or chat without waiting, and read them exactly as they were made in Office. Large workbooks and long presentations open fast too.
  • Export to PDF and images: export to PDF or PNG from the command line without opening a window — ready for batch conversion and automated processing on servers.

Web edition (WebAssembly + WebGPU)

  • Use it without installing anything: just open it in the browser to view and edit documents with the same screen and the same rendering as the desktop app. Works on PCs where you cannot install software and on shared machines.
  • Build document viewing and editing into web systems: inside business systems, SaaS products and portals, view and edit attached Word, Excel and PowerPoint documents on the spot, looking just as they do in Office.
  • Handle documents without sending them to a server: rendering and editing happen inside the browser, so when you open a local file its content is not sent to any external server.

Building

git clone --recurse-submodules https://github.com/ibisjp/ibis-office.git
cd ibis-office
cargo build --release
  • On Windows, build with cargo build --release -p ibis-office-app (the whole workspace includes a Linux-only crate); the app is target\release\ibisOffice.exe.
  • On macOS, scripts/bundle-macos.sh --release builds the app at target/release/ibisOffice.app.
  • On Linux, scripts/bundle-linux.sh --release builds an AppImage at target/dist/ibisOffice--Linux.AppImage, and scripts/bundle-flatpak.sh --release a Flatpak bundle at target/dist/ibisOffice--Linux-.flatpak (needs flatpak-builder).
  • For the browser edition, build with scripts/build-web.sh --release and serve www/ (browsers with WebGPU: Chrome, Edge, Safari 26 or later).

Implemented Features

ibisOffice implements a comprehensive set of features for Word (.docx), Excel (.xlsx), and PowerPoint (.pptx) documents, strictly compliant with the ECMA-376 specification.

For the full list of implemented features across all three formats (over 1,800 items), please see:

👉 Implemented Features

License

ibisOffice is dual-licensed under AGPL-3.0-only and a commercial license.

  • AGPL-3.0: free to use, modify and distribute as open source. If you offer a modified version as a service over a network, you must also publish its source under AGPL-3.0. See LICENSE.
  • Commercial license: if you build ibisOffice into a product or service that cannot meet the AGPL-3.0 terms (publishing the source), please use the commercial license. See COMMERCIAL-LICENSE.md.

All copyrights in ibisOffice are held by ibis inc., which is what allows it to be offered under both licenses.

The components we use and the notices their licenses require are listed in THIRD-PARTY-NOTICES.md (for each build: www/license.md, crates/ibis-office-app/macos/license.md, crates/ibis-office-app/linux/license.md). Our modified forks of GPUI (Apache-2.0) are published as gpui-pre, gpui-pre-macos, gpui-pre-windows, gpui-pre-linux, gpui-pre-wgpu and gpui-pre-web.

Contributing

Bug reports, requests and proposed fixes are welcome in Issues (we do not accept pull requests at the moment). For an issue with code, a one-line reply to our CLA lets us use it; see CONTRIBUTING.md. Please report security issues through the channels in SECURITY.md, not in Issues.

Trademarks

Microsoft, Microsoft Office, Microsoft 365, Word, Excel and PowerPoint are registered trademarks or trademarks of Microsoft Corporation in the United States and other countries. LibreOffice is a registered trademark or trademark of The Document Foundation, and ONLYOFFICE of Ascensio System SIA. All other company and product names are registered trademarks or trademarks of their respective owners. ibisOffice is not affiliated with, endorsed by or sponsored by any of these companies.

The ibisOffice name and logo are trademarks of ibis inc. See TRADEMARK.md for how to use them. Anything based on ibisOffice must display "Powered by ibisOffice".

© ibis inc.

Frequently asked questions

Is ibis-office free to use?

ibis-office is open source under the AGPL-3.0 licence. There is no licence fee and no seat count — you can self-host it or, where the project offers one, pay a vendor for a managed version instead.

What does ibis-office do?

The next-gen Office suite built with Rust & GPUI. Blazing-fast, memory-safe, and highly accurate editing for DOCX, XLSX, and PPTX with pixel-perfect rendering.

What is ibis-office written in?

ibis-office is primarily written in Rust. Its source is publicly available at https://github.com/ibisjp/ibis-office, and it has 525 GitHub stars.