Reuse all tools controls whether LispWorks uses an existing tool rather than starting up a new copy. For example if Reuse all tools is checked, if an editor is already open, choosing File > Open and selecting a new file causes the file to be opened in the existing editor.
Use separate Editor windows for each file controls whether LispWorks will open a separate Editor window for each file (or editor buffer) that you have in memory. In addition, when Use separate Editor windows for each file is checked, closing an Editor window will remove the underlying editor buffer from memory, possibly asking if you want to save it. The default setting is unchecked.
Note: for information about Editor windows, editor buffers and files, see Displaying and swapping between buffers.
By default a floating window offers access to the various IDE tools on Cocoa. If you do not want this, deselect the Show the tools on a floating toolbar option.
Check Use recent directory for opening files to make operations such as File > Open use the directory of the file most recently edited as the default directory in the file dialog. Deselect this option to make the dialog's default directory be the current working directory.
Note: this option does not affect the Editor tool, for which the file dialog always uses the directory of the currently visible file as the default directory.
LispWorks IDE User Guide (Macintosh version) - 25 Nov 2011