Ranked #1 on Hacker News with 153 points and 63 comments.
Cobalt is an open-source application platform for Kobo e-readers: a launcher, a signed App Store, a Rust SDK, and a runtime that keeps every app in its own unprivileged process.
Install it once over USB. Every app after that installs, updates and removes on the reader itself, over Wi-Fi. A reboot returns to the stock Kobo reader.
Every app is a static ARM binary running as its own unprivileged process on stock hardware. The App Store installs, updates and removes them over Wi-Fi, with signatures verified before anything launches.
arXiv papers and coding agents, on the panel.
These are photographs of the device, not simulator captures. The arXiv app reads the HTML rendering arXiv publishes for every paper since December 2023: abstracts, sections, math and result tables, paginated for the panel.
Every screenshot below is a capture from a Kobo Clara BW. Store apps version independently of the platform; the rest ship with the platform install.