Entries in the System Browser can be sorted in a number of ways. To change the sorting, choose Tools > Preferences... or click to display the Preferences dialog, and then select System Browser in the list on the left side of the dialog. Click on the General tab to view the sorting options.
Sorts entries in the main area of the current view (the tree in the tree view and the Files area in the text view) according to the symbol name.
Sorts entries in the main area according to their package.
Leave entries in the main area unsorted. This is the default setting.
LispWorks IDE User Guide (Windows version) - 25 Nov 2011