doc: add license requirements file

Add a documentation file that describes license requirements and
compliance information.

Signed-off-by: Danny Holman <dholman@gymli.org>

2 files changed, 46 insertions, 1 deletions

diff --git a/doc/index.rst b/doc/index.rst
index b4dfb5a..0187820 100644
--- a/doc/index.rst
+++ b/doc/index.rst
@@ -25,12 +25,12 @@ trying to get the engine to work for their own applications or libraries.
 
    Introduction <introduction.rst>
    List of features <feature-list.rst>
+   License requirements <license-requirements.rst>
    Core API <core/index.rst>
    Network API <network/index.rst>
    Rendering API <render/index.rst>
    UI API <ui/index.rst>
    Sound API <sound/index.rst>
-   Reporting issues <reporting-issues.rst>
 
 Working with upstream
 ---------------------
diff --git a/doc/license-requirements.rst b/doc/license-requirements.rst
new file mode 100644
index 0000000..828a477
--- /dev/null
+++ b/doc/license-requirements.rst
@@ -0,0 +1,45 @@
+License requirements
+====================
+
+Note: this manual is *not* intended for legal advice. It is provided to aid
+users navigate license and copyright requirements.
+
+What are licenses?
+------------------
+
+Rune is created and distributed under the `zlib license
+<https://opensource.org/license/zlib>`_. It doesn't have a sole owner, as every
+contributor that submits code or other technical contributions does so under the
+same license and retains ownership of their contribution.
+
+The license is a legal requirement for you (or your company) to use and
+distribute the software. Your application can have a different license, but it
+still needs to comply with the original one.
+
+Requirements
+------------
+
+For the zlib license, as long as you aren't altering any engine source files and
+distributing them, there are no hard license requirements. However, if you do
+decide it is best to modify the engine for your own needs, you would need to
+mark these altered sources as modified from the original and that you made the
+modification(s).
+
+If you use Rune in your application as-is, an acknowledgement in your
+application or documentation is appreciated but not required.
+
+For code that is bundled with or used by Rune itself, there is a section at the
+end of this document that lists requirements for those.
+
+Third-party licenses
+--------------------
+
+Rune itself contains software written by third parties, which is compatible
+with, but not covered by Rune's zlib license. Most, if not all, of these
+dependencies are distributed under permissive open source licenses which require
+attribution by explicitly citing their copyright statement and license text in
+the final product's documentation.
+
+Since the Rune Engine is so large, this can be difficult to do. A good option is
+to include this file in your project's distribution, and you can rename it to
+something suitable to avoid confusion with your own code and assets.