WordCraft, GridCraft, and DeckCraft — open-source, AI-built replicas of Microsoft Word, Excel, and PowerPoint, are now available for download. Developer Brandon Thomas built all three using Anthropic’s Claude Opus 5.5, the same model he used to create PhotoCraft, the AI-generated Photoshop alternative released earlier this year. The apps are written in Rust, run natively on Windows, macOS, Linux, and BSD, and compile to WebAssembly for browser use. No Electron or Tauri wrappers. They’re licensed under MIT or Apache 2.0 and hosted on GitHub. No commercial distribution or cloud dependency is required. All three are in alpha. None are ready for production use, but they’re functional enough to open, edit, and save native Office files offline. WordCraft reads.docx, writes PDFs with selectable text and bookmarks, and implements mail merge. GridCraft supports.xlsx and claims 89% of Excel’s ribbon commands and 98% of its worksheet functions. DeckCraft opens.pptx and reports 79% feature parity across 191 PowerPoint features. Including advanced formatting and PDF export. WordCraft is the most mature: 88% of Word’s ribbon commands implemented, ~60% feature parity. GridCraft is roughly 50% “ready for real work”, DeckCraft about 55%. Thomas has not announced pricing, all three are free. No official release date or beta timeline is given. The GitHub repos are live. Users can clone, build, and test now. If they’re comfortable with alpha software that lacks spellcheck in some languages, incomplete macro support, and no real-time collaboration. This isn’t a Microsoft Office replacement. It’s a proof point: clean-room reimplementations, guided by Claude, can now reach mid-fidelity in complex desktop productivity suites, without access to proprietary code or APIs. Next step? Community contributions. The repos accept pull requests.