John Crenshaw

software engineer, ret.

I write essays and build Rust tools for the Linux desktop.

I built other people's software since the 80s. Payment rails moving debit, credit, and ACH. HIPAA data mining. Retinal biometric access for the DoD. EPROM tooling against Intel silicon that hadn't shipped yet. The backend systems you never see. Retired now. These days I build my own, in Rust, for the Linux desktop I actually run.

one hand

The writing and the tools come from the same desk.

The tools prove the essays, the essays explain the tools.

Writing

The Last Default

Jul 12, 2026 · 7 min read

The always-on laptop running my home network kernel panicked on Ubuntu, and I took the crash as the excuse I'd been waiting for. Here's the security-first…

Read the argument →

Tools live

cosmic-ext-applet-tempest

Rust v2.11.0 Flatpak

Latest release · Jul 10, 2026

A weather applet for COSMIC: forecasts, alerts, and air quality with no account or API key.

Get it on GitHub ↗

Browse the code on GitHub ↗

John Crenshaw — essays and Rust tools for the Linux desktop

The writing and the tools come from the same desk.