Docker Desktop
Free · macOS / Windows / Linux
Runs the sandboxed Chromium that opens your suspicious link. Without it, LinkCage has nowhere to send links.
How to install
Download the installer for your OS, run it, and accept the defaults. On first launch, Docker Desktop will set up its own engine — give it a minute. You'll know it's ready when the whale icon appears in your menu bar (macOS) or system tray (Windows).
Check it's working:
docker --version