Ncat is (C) 2005–2012 Insecure.Com LLC. It is distributed as free and open source software under the same license terms as our Nmap software. Precise terms and further details are available in the section called “Nmap Copyright and Licensing”.

This Ncat Reference Guide is (C) 2005–2012 Insecure.Com LLC. It is hereby placed under version 3.0 of the Creative Commons Attribution License. This allows you redistribute and modify the work as you desire, as long as you credit the original source. Alternatively, you may choose to treat this document as falling under the same license as Ncap itself (discussed previously).

Source is provided to this software because we believe users have a right to know exactly what a program is going to do before they run it. This also allows you to audit the software for security holes (none have been found so far).

Source code also allows you to port Nmap (which includes Ncat) to new platforms, fix bugs, and add new features. You are highly encouraged to send your changes to <dev@nmap.org> for possible incorporation into the main distribution. By sending these changes to Fyodor or one of the Insecure.Org development mailing lists, it is assumed that you are offering the Nmap Project (Insecure.Com LLC) the unlimited, non-exclusive right to reuse, modify, and relicense the code. Nmap will always be available open source, but this is important because the inability to relicense code has caused devastating problems for other Free Software projects (such as KDE and NASM). We also occasionally relicense the code to third parties as discussed in the Nmap man page. If you wish to specify special license conditions of your contributions, just say so when you send them.

This program 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 v2.0 for more details at http://www.gnu.org/licenses/gpl-2.0.html, or in the COPYING file included with Nmap.

Ncat should never be installed with special privileges (e.g. suid root). That would open up a major security vulnerability as other users on the system (or attackers) could use it for privilege escalation.

This product includes software developed by the Apache Software Foundation. A modified version of the Libpcap portable packet capture library is distributed along with Ncat. The Windows version of Ncat utilized the Libpcap-derived WinPcap library instead. Certain raw networking functions use the Libdnet networking library, which was written by Dug Song. A modified version is distributed with Ncat. Ncat can optionally link with the OpenSSL cryptography toolkit for SSL version detection support. All of the third-party software described in this paragraph is freely redistributable under BSD-style software licenses.