exe is a personal VM cloud: a single binary running on this machine that creates persistent Linux virtual machines, lets you (and AI agents) work inside them over SSH, and can publish any VM port to a real HTTPS address through your Cloudflare Tunnel. This desktop is its control panel — and everything you see here can also be driven from a terminal or by an agent over HTTP and SSH.
On the documentation website, the toolbar's joined sun and moon buttons choose light or dark paper. The pressed segment shows the current choice, which this browser remembers between visits.