libtu
-Copyright (c) Tuomo Valkonen 1999-2004.
+Copyright (c) Tuomo Valkonen 1999-2007.
<tuomov at iki.fi>
system's versions of these functions, if available, modify
system.mk.
+The implementation of red-black trees is based on that by
+James S. Plank; see README.rb for details.