Ksplice allows system administrators to apply patches to their
operating system kernels without rebooting.  Unlike previous hot
update systems, Ksplice operates at the object code layer, which
allows Ksplice to transform many traditional source code patches into
hot updates with little or no programmer involvement.  In the common
case that a patch does not change the semantics of persistent data
structures, Ksplice can create a hot update without a programmer
writing any new code.