This library deals with the very system dependent task of opening a 
web page in a browser. See also library(url) and the HTTP 
package.
- www_open_url(+URL)
 - 
Open URL in an external web-browser. The reason to place this 
in the library is to centralise the maintenance on this highly platform 
and browser specific task. It distinguishes between the following cases:
- MS-Windows
If it detects MS-Windows it uses win_shell/2 
to open the URL. The behaviour and browser started depends on 
the Window and Windows-shell configuration, but in general it should be 
the behaviour expected by the user.
 - Other platforms
On other platforms it tests the environment variable (see getenv/1) 
named BROWSER or uses netscape if this variable is 
not set. If the browser is either mozilla or netscape,
www_open_url/1 
first tries to open a new window on a running using the -remote 
option of netscape. If this fails or the browser is not mozilla 
or netscape the system simply passes the URL as first 
argument to the program.