BYOS: Replacing 25 years of vim in 72 hours with Claude Code

A developer documents replacing nearly every tool in his daily computing environment with custom-built alternatives, leaning on Claude Code as a coding workhorse. The stack splits cleanly: CHasm handles low-level work in pure x86_64 assembly without libc, while Fe₂O₃ provides the Rust application layer atop a small shared TUI library called crust. What remains off-the-shelf is minimal — WeeChat for chat and Firefox for the rare GUI need.

The headline data point is vim. Twenty-five years of muscle memory got rerouted to a custom modal editor called scribe in seventy-two hours. Scribe drops the ninety percent of vim features the author never used and bakes in writer-shaped additions: soft-wrap defaults, Limelight-style focus mode, in-buffer AI prompts, HyperList syntax with encryption support, and registers shared across concurrent sessions.

The broader argument is economic. Building your own editor, file manager, or window manager used to be a multi-year project that rarely shipped. Rust, well-documented TUI patterns, and AI coding assistants have collapsed that cost by orders of magnitude — the gap between wishing a tool did X and shipping a tool that does X now fits in a few evenings. Designing for an audience of one strips out the complexity of configurability, edge cases, and documentation, leaving software that is small, fast, and exactly shaped to its single user.