1.  Fortran code: 

Copyrighted and Licensed by ACM, 
see http://www.acm.org/publications/policies/software-copyright-notice


2. R interface and extensions related to Voronoi mosaics
(src/voronoi.f, src/left.f): 

The R interface code has been developed as work based on the 
ACM licensed code, hence it is also ACM licensed, copyright 
is by A. Gebhardt <albrecht.gebhardt@aau.at>. 

In order to fulfill the ACM copyright and license noted above, 
it is stated here that this work contains modified ACM material, 
and to fulfill this, the modified work including the R interface 
is available free to secondary users, and no charge is associated 
with such copies.

3. Helper functions taken from SLATEC (src/dsos.f src/func.f):

Public domain (according to http://en.wikipedia.org/wiki/Netlib)