Developer Creates Free Microsoft Office Alternatives Using AI in Under Two Weeks

Brandon Thomas Targets Microsoft Office with AI Software Development

Brandon Thomas, the developer who recently cloned Adobe's Creative Cloud suite, has now turned his attention to Microsoft Office alternatives. Less than two weeks after releasing ArtCraft—his Photoshop clone—Thomas published open-source replicas of Word, Excel, and PowerPoint on GitHub1

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. Named WordCraft, GridCraft, and DeckCraft respectively, these free alternatives to Microsoft Office were built using Anthropic's Claude Opus 5.5 and written in Rust1

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. The speed at which Thomas developed these applications demonstrates how AI-assisted developer tools can accelerate complex software creation—a process that traditionally required years of work by large developer communities.

Open-Source Replicas Challenge $99.99 Annual Microsoft 365 Subscription

The three applications are available under MIT or Apache 2.0 licenses, allowing anyone to read, copy, modify, and even commercially reuse the code2

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. This directly challenges Microsoft's pricing model, where Microsoft 365 Personal costs $99.99 per year and the family plan runs $129.99 annually2

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. Thomas calls the project a clean-room rebuild, meaning the apps were written from public file-format specifications and by observing how the originals behave, without copying Microsoft's code2

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. This approach mirrors the legal strategy Compaq used to clone IBM's PC BIOS in the 1980s. All three applications use a single Rust codebase that runs natively on Windows, macOS, Linux, and BSD, and can also function in web browsers via WebAssembly1

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WordCraft Achieves 88% Feature Parity with Microsoft Word

WordCraft is the most developed of the three applications, implementing 88% of Word's ribbon commands1

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. The application reads and writes .docx, Word's native file format, and supports additional formats including .odt, .rtf, .html, .md, and .txt1

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. It can also import the legacy .doc format and export PDFs with selectable text, links, and bookmarks. Critical features like spelling, grammar, track changes, footnotes, citations, and mail merge already work offline1

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. The mail merge feature lets users create personalized letters by pulling data from CSV files or Outlook contacts. Despite this progress, the development team estimates WordCraft has reached only about 60% overall feature parity when considering file fidelity and stability1

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. At just 91MB, early testers report it feels snappy and looks almost identical to Microsoft Word2

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GridCraft Implements 98% of Excel Worksheet Functions

GridCraft, the Excel alternative, already handles 513 of Excel's 523 worksheet functions—formulas like SUM and VLOOKUP that power spreadsheet calculations2

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. This represents approximately 98% of Excel's worksheet functions1

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. The application implements about 89% of Excel's ribbon commands and offers the familiar interface including the ribbon, formula bar, and keyboard shortcuts1

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. GridCraft uses .xlsx as its native file format and is fully scriptable by AI agents1

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. However, developers rate it only about 50% ready for real work, with compatibility on real-world .xlsx files next on the development roadmap1

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. While it knows almost every formula, it may still struggle with complex company spreadsheets that use advanced formatting or specialized elements.

DeckCraft Targets PowerPoint with 79% Feature Coverage

DeckCraft, the PowerPoint stand-in, covers approximately 79% of PowerPoint's features across 191 functions and 93% of core features1

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. The application opens and saves .pptx files, runs transitions and animations, and exports to PDF1

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. It aims for full feature parity with PowerPoint and to be "better and faster" than the original1

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. The project estimates DeckCraft is around 55% ready for real work1

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. DeckCraft hasn't reached its first alpha release yet, making it the least developed of the three applications2

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. All three apps are currently in alpha testing, an early development stage where bugs are expected.

AI Agent Capabilities Through Model Context Protocol Integration

Every button in all three applications doubles as a command that an AI agent can trigger2

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. The apps plug in through MCP, the Model Context Protocol—a standard Anthropic created so AI models can operate tools externally2

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. In practice, users could ask Claude to build a chart in GridCraft or reformat a report in WordCraft without touching the mouse. This integration represents a significant departure from traditional office software, positioning these tools at the intersection of productivity applications and AI-powered automation. The model behind the ArtCraft project, Claude Opus 5.5, launched on September 22 at $4 per million input tokens and $20 per million output tokens2

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. On Terminal-Bench 4.0, which tests whether an AI agent can finish complex professional tasks in a command-line environment, Opus 5.5 scored 66.4%2

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Cross-Platform Compatibility and Future Development Challenges

The applications target Windows, macOS, and Linux, with their cross-platform approach allowing developers to inspect code, contribute improvements, and adapt the software to specific requirements3

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. However, compatibility remains a key challenge—complex layouts, advanced formatting, and documents containing specialized elements may not render exactly as they do in Microsoft Office applications3

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. Thomas has a history of promising more than his apps initially deliver. He already walked back his pledge to match Adobe's feature set within a month for the ArtCraft project2

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. Despite this, WordCraft had collected more than 12,000 GitHub stars as of publication, indicating strong community interest2

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. Free Office alternatives have existed for decades—OpenOffice.org launched in October 2000 when Sun Microsystems released StarOffice's code, and LibreOffice split from it in 20102

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. Both took years of work by large developer communities, making Thomas's two-week timeline particularly notable for demonstrating AI software development capabilities. Watch whether these applications can achieve sufficient stability and feature completeness to challenge established productivity suites, and how Microsoft responds to this direct challenge to its subscription model.