License

Original Author: 1993-2013 Daniel Garcia-Castellanos.

tAo is free open-source software; you can redistribute it and/or 
modify it under a GNU GPL v3 license. For non-code contents use a Creative
Commons 3.0 BY-SA license  (you  must cite the  original authorship and
share your versions alike). 
The scientific citation is:

Garcia-Castellanos, D., M. Fernandez & M. Torne, 2002. Modelling the 
evolution of the Guadalquivir foreland basin (South Spain). 
Tectonics 21(3), doi:10.1029/2001TC001339 [pdf]

This means approximately (but look at the GNU-GPL license) that you could
use/add/modify the code, but the resulting code you produce must:
1) be open (public domain) and follow the present copyleft-method rule.
2) contain references to the original authorship and to the copyleft rule
at the beginning of each file containing copyleft material. 
3) In particular, commercial use of part of the present code must be
previously authorised by the author(s) of the code parts under copyleft
rule. 

This software is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.