zlib/libpng license

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.

  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.

  3. This notice may not be removed or altered from any source distribution.

				--

The source code in prime.mix, mystery.mix, and elevator.mix and the
text in MIX.DOC are excerpted from "The Art Of Computer Programming".
Addison-Wesley and Donald Knuth have specifically granted permission
for this material and all other MIX code examples from that book to be
distributed in conjunction with any open-source implementation of MIX
under the license(s) applying to that implementation.

The code is Copyright (c) 1994 by Darius Bacon. It was originally
distributed under a custom license isomorphic to the zlib/libpng
license given above. ESR changed it because custom licenses confuse 
catalog systems like Freshmeat.