development.md

 # Development
 
-* [instructions](https://gitlab.labs.nic.cz/labs/jetconf/wikis/devinstall)
+* [Instructions](https://gitlab.labs.nic.cz/labs/jetconf/wikis/devinstall)
   for installing the development environment
-* [tools and rules](https://gitlab.labs.nic.cz/labs/jetconf/wikis/tools-rules)
-* [libdan API docs](libdan-api)
+
+# Tools and Rules
+
+## Programming Style
+
+We can mostly follow [Google Python Style Guide](https://google.github.io/styleguide/pyguide.html).
+
+All module-level functions and class/object methods should be annotated with type hints. For other values, type hints should be used where it seems important. See [PEP 0484](https://www.python.org/dev/peps/pep-0484/).
+
+## Static Type Checking
+
+Later we might use [mypy](http://mypy-lang.org). Currently it doesn't work well will Python 3.5.
+
+## Unit Tests
+
+We use [pytest](http://pytest.org).
+
+## Documentation
+
+We will use [Sphinx](http://www.sphinx-doc.org/en/stable/) for creating documentation. Docstrings in the code should therefore use Sphinx directives, see this [example](http://www.sphinx-doc.org/en/stable/domains.html#info-field-lists).