




The function 
default-library
 returns a keyword naming the the default library.
On Unix/Linux platforms, currently the only library available is 
:motif
, hence this is the default library.
On Microsoft Windows platforms, currently the only library available is 
:win32
, hence this is the default library.
On Mac OS X platforms, currently the only library available is 
:cocoa
, hence this is the default library.