☰ → Settings → Set as default browser… registers Vodou with your operating system as a browser it can hand links to. What happens next depends on your OS — neither Windows nor Linux lets an application flip the actual default silently, and for good reason.

Windows

Vodou writes the registration to your Windows user account (no administrator rights needed), then opens Settings → Apps → Default apps for you. Windows has ignored programmatic default-browser changes since Windows 8, so find Vodou (or the http/https/.htm/.html entries) in that list and switch them over yourself.

Linux

Vodou runs xdg-settings set default-web-browser vodou.desktop, which most desktop environments accept immediately with no extra confirmation step. This needs Vodou's application launcher to already be installed — run packaging/install-linux.sh first if you haven't (see Installing Vodou).

macOS

Not available yet — Vodou isn't packaged as a macOS app bundle, which is what macOS requires in order to register a default-browser handler.

Why this matters

Once Vodou is your default, clicking a link in another app (an email, a chat message, a PDF) opens that exact page in Vodou instead of just showing your start page.