+ saved core is loaded.
+
+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.
+
+This implementation is not as polished and painless as you might like:
+ * It corrupts the current Lisp image enough that the current process
+ needs to be killed afterwards. This can be worked around by forking
+ another process that saves the core.
+ * It will not work if multiple threads are in use.
+ * There is absolutely no binary compatibility of core images between
+ different runtime support programs. Even runtimes built from the same
+ sources at different times are treated as incompatible for this
+ purpose.
+This isn't because we like it this way, but just because there don't
+seem to be good quick fixes for either limitation and no one has been
+sufficiently motivated to do lengthy fixes."