.. _qgis.documentation.preamble: ******** Preamble ******** This document is the original user guide of the described software QGIS. The software and hardware described in this document are in most cases registered trademarks and are therefore subject to legal requirements. QGIS is subject to the GNU General Public License. Find more information on the QGIS homepage, https://www.qgis.org. The details, data, and results in this document have been written and verified to the best of the knowledge and responsibility of the authors and editors. Nevertheless, mistakes concerning the content are possible. Therefore, data are not liable to any duties or guarantees. The authors, editors and publishers do not take any responsibility or liability for failures and their consequences. You are always welcome to report possible mistakes. This document has been typeset with reStructuredText. It is available as reST source code via `github `_ and online as HTML and PDF via https://www.qgis.org/en/docs/. Translated versions of this document can be downloaded in several formats via the documentation area of the QGIS project as well. For more information about contributing to this document and about translating it, please visit https://qgis.org/en/site/getinvolved/index.html. **Links in this Document** This document contains internal and external links. Clicking on an internal link moves within the document, while clicking on an external link opens an internet address. In PDF form, internal and external links are shown in blue and are handled by the system browser. In HTML form, the browser displays and handles both identically. **User, Installation and Coding Guide Authors and Editors:** The list of the persons who contribute on writing, reviewing and translating the following documentation is available at :ref:`doc_contributors`. Copyright (c) 2004 - 2017 QGIS Development Team **Internet:** https://www.qgis.org **License of this document** Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts and no Back-Cover Texts. A copy of the license is included in Appendix :ref:`gfl_appendix`.