Expunge Libraries:

  With this checkmark you can decide wether  the  memory  used  by  already
  loaded libraries  should  be  released or not, when you quit the program.
  
  If you often quit and reload the APlayer, then this button will help you.
  As  it  will  prevent the player libraries, agents  and noteplayers  from
  being  loaded everytime  you restart  the player  and load a  new kind of
  module.

  Because most people want  to  have  as  much  memory  as  possible,  this
  function is by default set to ON.

  Default is ON.