Browser is a Chromium browser (Microsoft Edge WebView2) that opens over the game. It works in workspaces: each workspace is its own browser profile with its own sign-ins, kept by overlay.win.
Workspaces
Give a workspace a name and choose Remember me (sign-ins and site data are kept) or Private (everything is forgotten when it closes).
Separate on purpose
Nothing is read from your other browsers, and a workspace never sees another workspace's sign-ins.
Everyday browsing
Tabs, back, forward, reload and stop, a home page and an address bar that searches or opens an address.
Stays over the game
Look something up, then close it with Insert. The game keeps its focus.
Out of captures
Like every overlay.win window it stays out of screen capture while Private overlay mode is on, so your stream shows the game.