You can move the Track Library window like any other window.

However, if you move it near the top or the bottom of the main AnyRail window, it will "dock", that is, become part of the main window.

 

TIP: To disable docking, go to Options in the File tab.

Page url: http://www.anyrail.com/help_en/index.html?docking_and_undocking_a_librar.htm