First look: Though vibe-coded apps are often slammed as "AI slop" by users and developers alike, generative AI can now produce complex productivity apps that rival market leaders. After building free, open-source alternatives to Adobe's Creative Cloud apps using Claude AI, developer Brandon Thomas is now turning to replicas of Microsoft Office apps like Word, Excel, and PowerPoint.
Called WordCraft, GridCraft, and DeckCraft, respectively, the open-source applications are written in Rust with Anthropic's Claude Opus 5.5, as the Adobe replicas were, and are available for download under MIT or Apache 2.0 licenses. They are, however, still at a relatively early stage of development and need a lot more work before they can be considered viable alternatives to Microsoft Office.
According to its GitHub page, WordCraft is an "open-source, clean-room reimplementation of Microsoft Word" that runs natively on Windows, macOS, Linux, and BSD. It can also be used in the browser via WebAssembly. The app uses a single Rust codebase for all platforms, without falling back on Electron or Tauri.
WordCraft reads and writes .docx, the native file format of Microsoft Word. It also supports a range of other formats, including .odt, .rtf, .html, .md, and .txt, and can import the legacy .doc format. It can export PDFs with real, selectable text, links, and bookmarks, too. Thomas noted that spelling, grammar, and many other critical features work offline.
WordCraft is visually almost identical to the software it's modeled after, offering the same ribbon, styles, tables, track changes, and references as Word. It also implements features like mail merge, which lets users create personalized letters by pulling in data from a CSV file or Outlook contacts list.
GridCraft, which replicates Microsoft Excel, already implements 89% of Excel's ribbon and menu commands, according to the developer, and about 98% of its worksheet functions. It offers Excel's familiar interface, including the ribbon, formula bar, keyboard shortcuts, and more. It uses .xlsx as its native file format and is fully scriptable by AI agents.
DeckCraft, which opens and saves .pptx files, aims for full feature parity with PowerPoint and to be "better and faster" than the original. Its GitHub page claims 79% "feature parity" across 191 PowerPoint features, including advanced formatting, and export to PDF.
WordCraft development is the furthest along, with 88% of Word's ribbon-based commands implemented.
Overall, the project estimates it has reached around 60% feature parity with the Microsoft app. All three apps are in alpha, with GridCraft around 50% "ready for real work" and DeckCraft around 55%.