You can download here the of SISCone source code. It is developped under the terms of the GNU General Public License (GPL). A version of the license should be included in the code.
The algorithm used by SISCone has been subject of a publication in arXiv:hep-ph/0701nnn. Please refer to that work each time it is appropriate.
You can alternatively download SISCone from its SVN repository hosted by HEPforge.