4.2.2 Delivering the application in memory

You can save time when experimenting with delivery parameters by delivering the application in memory rather than saving it to disk.

If the deliver keyword :in-memory-delivery is non- nil , the delivered image is not saved to disk, but instead starts up automatically after the delivery operations are complete.

For example, a good early test is

(deliver 'user:run
                 :in-memory-delivery t)

Note: The image exits as soon as the application terminates.

LispWorks Delivery User Guide - 12 Sep 2005