What will happen once user closes last browser window with the site in it?
SPWS will stay running in background, in order next time CDROM is inserted or browser-based application is run, the browser page will appear immediately. The SPWS processes will be terminated on the user’s logoff. But it’s greatly recommended to put some kind of “release CDROM” button on link to your site, otherwise users of operating systems other than Windows will be unable to eject CDROM with SPWS on it. There is a special support for stopping and releasing media in SPWS.