-Foreign objects loaded with SB-ALIEN:LOAD-SHARED-OBJECT are
-automatically reloaded on startup, but references to foreign symbols
-do not survive intact on all platforms: in this case a WARNING is
-signalled when saving the core. If no warning is signalled, then the
-foreign symbol references will remain intact. Platforms where this is
-currently the case are x86/FreeBSD, x86/Linux, x86/NetBSD,
-sparc/Linux, sparc/SunOS, and ppc/Darwin.
+Foreign objects loaded with SB-ALIEN:LOAD-SHARED-OBJECT are automatically
+reloaded on startup, but references to foreign symbols do not survive intact
+on all platforms: in this case a WARNING is signalled when saving the core. If
+no warning is signalled, then the foreign symbol references will remain
+intact. Platforms where this is currently the case are x86/FreeBSD, x86/Linux,
+x86/NetBSD, sparc/Linux, sparc/SunOS, and ppc/Darwin.
+
+On threaded platforms only a single thread may remain running after
+SB-EXT:*SAVE-HOOKS* have run. Applications using multiple threads can
+be SAVE-LISP-AND-DIE friendly by registering a save-hook that quits
+any additional threads, and an init-hook that restarts them.