Most desktop app tooling has trended toward bundling a browser runtime with every binary, but TinyJS takes the opposite approach. The Register reports that developer Tarwin Stroh-Spijer built TinyJS as a JavaScript runtime that renders apps through the webview already present in macOS, Windows, and Linux. That means a typical app can fit in roughly 6MB, while even a minimal Electron app can weigh 150MB.
TinyJS is built on txiki.js, an ultra-compact JavaScript runtime, and uses the OS's interprocess communication for data transfer, avoiding the need to ship an HTTP server. Developers write in JavaScript, CSS, and HTML, and no compilation is required. The trade-off is that because each OS renders web content slightly differently, an app's look can vary across platforms, unlike Electron's uniform Chromium rendering.
Stroh-Spijer also runs a desktop app store with 25 sample apps, including a world clock, SQLite browser, and Winamp clone, all under 8MB. The project is similar in spirit to Tauri, which can produce 10MB apps, but TinyJS avoids Tauri's requirement to write in Rust. The Register notes some rough edges: the launcher needs to be trusted by Windows Defender, and a clipboard app was buggy on Windows in testing. Still, the project points to a lighter path for small desktop utilities.