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+
+Virtual DOM
+===========
+
+The virtual dom is in the ``vdom`` module.
+
+The ``VNodeKind`` enum describes every tag that the HTML 5 spec includes
+and some extensions that allow for an efficient component system.
+
+These extensions are:
+
+``VNodeKind.int``
+     The node havs a single integer field.
+
+``VNodeKind.bool``
+     The node has a single boolean field.
+
+``VNodeKint.vthunk``
+     The node is a `virtual thunk`:idx:. This means there is a
+     function attached to it that produces the ``VNode`` structure
+     on demand.
+
+``VNodeKint.dthunk``
+     The node is a `DOM thunk`:idx:. This means there is a
+     function attached to it that produces the ``Node`` DOM structure
+     on demand.
+
+For convenience of the resulting Nim DSL these tags have enum names
+that differ from their HTML equivalent:
+
+=================     =======================================================
+Enum value            HTML
+=================     =======================================================
+``tdiv``              ``div``  (changed because ``div`` is a keyword in Nim)
+``italic``            ``i``
+``bold``              ``b``
+``strikethrough``     ``s``
+``underlined``        ``u``
+=================     =======================================================
+
+
+A virtual dom node also has a special field set called ``key``, an integer
+that can be used as a data model specific key/id. It can be accessed in event
+handlers to change the data model. See the todoapp for an example of how to
+use it.
+
+**Note**: This is not a hint for the DOM diff algorithm, multipe nodes can
+all have the same key value.
+
+
+Event system
+============
+
+Karax does not abstract over the event system the DOM offers much: The same
+``Event`` structure is used. Every callback has the
+signature ``proc (ev: Event; n: VNode)``.
+
+