-*overlay-boot* attempts to run a "subhost" with an overlay root
-filesystem. The subhost is defined in a configuration file named on
-the command line. When all is good, *overlay-boot* spawns a subprocess
-that invokes a command shell within an chroot into "unshared" overlay
-root filesystem, to perform service initialisations before ending up
-in an indefinitely running "reaper" process. The overlay subhost is
-essentially like a light container or virtual virtual machine for
-running services in a relatively contained way without too much of
-cross-wise interactions between them.
+*overlay-boot* is the main script on a small collection of
+administration scripts for containerizing services with minimal ado.
+The script starts a "subhost" with a dedicated network namespace, and
+the mount and pid namespaces separated from the main host by means of
++unshare+. A subhost root file system may in particular be set up as
+an overlay of the main host filesystem to keep the specifics of a
+service distinctly separate from the main host while sharing files
+wherever sensible.
+
+A subhost is started by identifyinf its configuration file on the
+command line for *overlay-boot*. The configuration file is a plain
+text file with a small collection of "variables" that tell how the
+subhost is set up. When all is good, *overlay-boot* spawns a
+subprocess that invokes a command shell within an chroot into
+"unshared" subhost root filesystem, all similar to the bootup of any
+odd computer.
+
+The subhost execution environment may be "entered" to perform
+adminstrative tasks with *overlay-go*, and it is later stopped with
+*overlay-stop*.