The Befunge-93 specification is not open-source (yet), but it is freely
redistributable unmodified for non-commercial purposes.

The contributed Befunge-93 example sources are copyrighted by their respective
authors.  Except where otherwise noted, they are not open-source works,
but their contributors' willingness to allow them to be included in this
distribution implies that they are all freely redistributable unmodified for
non-commercial purposes.  If you wish to base your next best-selling novel
on one of them, you should seek out and contact its author for permission
first.  There is one exception: all Befunge-93 example sources in this
distribution which were written by Chris Pressey is in the public domain.

The source code for the reference interpreter and supporting tools (in the
`src` subdirectory) is covered under the following BSD-style license:

   Copyright (c)1993-2012, Chris Pressey, Cat's Eye Technologies.
   All rights reserved.
 
   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:

     Redistributions of source code must retain the above copyright
     notices, this list of conditions and the following disclaimer.

     Redistributions in binary form must reproduce the above copyright
     notices, this list of conditions, and the following disclaimer in
     the documentation and/or other materials provided with the
     distribution.

     Neither the names of the copyright holders nor the names of their
     contributors may be used to endorse or promote products derived
     from this software without specific prior written permission. 

   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES INCLUDING, BUT NOT
   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
   COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   POSSIBILITY OF SUCH DAMAGE.