If you carefully read the instructions, you can learn how to compile libraries with it - there is explicit support for this use case. (which is likely what jQuery have done.)<p>Exports:
<a href="http://code.google.com/closure/compiler/docs/api-tutorial3.html#export" rel="nofollow">http://code.google.com/closure/compiler/docs/api-tutorial3.h...</a><p>Extern:
<a href="http://code.google.com/closure/compiler/docs/api-tutorial3.html#externs" rel="nofollow">http://code.google.com/closure/compiler/docs/api-tutorial3.h...</a>