Developer Who Cloned Photoshop With AI Just Did the Same to Microsoft Office

In brief

Developer Brandon Thomas released WordCraft, GridCraft and DeckCraft, free open-source clones of Microsoft Word, Excel and PowerPoint written in Rust with help from Anthropic's Claude.

WordCraft covers 88% of Word's ribbon features and GridCraft handles 513 of Excel's 523 worksheet functions, but the team rates them only 50% to 60% ready for real work.

The release follows Thomas' ArtCraft clones of Adobe's apps and targets a Microsoft 365 subscription that costs $99.99 a year for a single user.

You have two options: Pay $100 every year for Microsoft Office online, or pay nothing for the vibe-coded “Office” clone that does basically the same and runs fully offline. Which do you pick?

The developer who used AI to rebuild Adobe's Creative Cloud for free has now turned to Microsoft Office, releasing open-source clones of Word, Excel, and PowerPoint built with Anthropic's Claude.

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Brandon Thomas, the engineer behind the ArtCraft project, published the apps on GitHub as WordCraft, GridCraft and DeckCraft. Open source means anyone can read, copy, and modify the code, and the MIT and Apache 2.0 licenses let people reuse it even commercially.

Earlier this month, Thomas made noise with ArtCraft, a set of free apps mirroring Photoshop, Illustrator, Premiere, and Lightroom, built with Claude Opus 5.5 after Adobe charged him its cancellation fee one too many times. It landed in the middle of a wave of AI cloning that has seen a developer get GTA V running natively on an iPhone and modders throw Minecraft creepers at an Elden Ring boss.

The Office clones are written in Rust, a programming language known for speed and for blocking the memory bugs that make software crash. A single codebase runs natively on Windows, macOS, Linux and BSD, and also inside a web browser.

Thomas calls the project a clean-room rebuild, meaning the apps were written from public file-format specifications and by watching how the originals behave, never by copying Microsoft's code. It's the same legal approach Compaq used to clone IBM's PC BIOS, the basic startup software of early PCs, back in the 1980s.

WordCraft reads and writes .docx, Word's native file format, and covers 88% of the features in Word's ribbon, the strip of tabs and buttons along the top of the screen. Track changes, footnotes, citations and mail merge—the tool that pulls names from a spreadsheet to personalize hundreds of letters—are already in.

Counting file fidelity and stability, though, the team estimates WordCraft is only about 60% of the way to replacing Word for real work. It's still labeled alpha, an early test version where bugs come standard.