Inkscape software license:

This program is free software and is distributed under the GNU General Public License, version 3. In short, this means you are free to use and distribute Inkscape for any purpose, commercial or non-commercial, without any restrictions. You are also free to modify the program as you wish, with the only restriction that if you distribute the modified version, you must provide access to its source code.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY. For more details about the license, check the link above or read the file COPYING in the folder share/inkscape/doc inside the Inkscape installation folder.

Licensing of files made using Inkscape:

All files either saved or exported from Inkscape in any format (SVG, PNG, PDF, etc.) are owned by the creators of the work (that's you!) and/or the original authors in case you use derivative works. 

You are responsible for publishing your work under a license of your choosing and for tracking your use of derivative works in the software. You can add and modify your license information for each file in the 'File/Document properties' dialog within Inkscape.
