Nikto is an open source project licensed under the GNU GPL license. As such, code updates are welcomed and very much appreciated.
The Nikto development source code is located in a Subversion (SVN) repository which is publicly accessible. To download the source code, install Subversion and issue the following command:
svn co http://svn2.assembla.com/svn/Nikto_2
For more information on the development enviornment, please see: http://www.assembla.com/spaces/Nikto_2/trac_subversion_tool