diff --git a/Doc/library/_ast.rst b/Doc/library/_ast.rst
new file mode 100644
index 0000000..80b8a37
--- /dev/null
+++ b/Doc/library/_ast.rst
@@ -0,0 +1,85 @@
+.. _ast:
+
+Abstract Syntax Trees
+=====================
+
+.. module:: _ast
+   :synopsis: Abstract Syntax Tree classes.
+
+.. sectionauthor:: Martin v. Löwis <martin@v.loewis.de>
+
+
+.. versionadded:: 2.5
+
+The ``_ast`` module helps Python applications to process trees of the Python
+abstract syntax grammar.  The abstract syntax itself might change with each
+Python release; this module helps to find out programmatically what the current
+grammar looks like.
+
+An abstract syntax tree can be generated by passing :data:`_ast.PyCF_ONLY_AST`
+as a flag to the :func:`compile` builtin function. The result will be a tree of
+objects whose classes all inherit from :class:`_ast.AST`.
+
+A modified abstract syntax tree can be compiled into a Python code object using
+the built-in :func:`compile` function.
+
+The actual classes are derived from the ``Parser/Python.asdl`` file, which is
+reproduced below. There is one class defined for each left-hand side symbol in
+the abstract grammar (for example, ``_ast.stmt`` or ``_ast.expr``). In addition,
+there is one class defined for each constructor on the right-hand side; these
+classes inherit from the classes for the left-hand side trees. For example,
+``_ast.BinOp`` inherits from ``_ast.expr``. For production rules with
+alternatives (aka "sums"), the left-hand side class is abstract: only instances
+of specific constructor nodes are ever created.
+
+Each concrete class has an attribute ``_fields`` which gives the names of all
+child nodes.
+
+Each instance of a concrete class has one attribute for each child node, of the
+type as defined in the grammar. For example, ``_ast.BinOp`` instances have an
+attribute ``left`` of type ``_ast.expr``.   Instances of ``_ast.expr`` and
+``_ast.stmt`` subclasses also have lineno and col_offset attributes.  The lineno
+is the line number of source text (1 indexed so the first line is line 1) and
+the col_offset is the utf8 byte offset of the first token that generated the
+node.  The utf8 offset is recorded because the parser uses utf8 internally.
+
+If these attributes are marked as optional in the grammar (using a question
+mark), the value might be ``None``. If the attributes can have zero-or-more
+values (marked with an asterisk), the values are represented as Python lists.
+All possible attributes must be present and have valid values when compiling an
+AST with :func:`compile`.
+
+The constructor of a class ``_ast.T`` parses their arguments as follows:
+
+* If there are positional arguments, there must be as many as there are items in
+  ``T._fields``; they will be assigned as attributes of these names.
+* If there are keyword arguments, they will set the attributes of the same names
+  to the given values.
+
+For example, to create and populate a ``UnaryOp`` node, you could use ::
+
+   node = _ast.UnaryOp()
+   node.op = _ast.USub()
+   node.operand = _ast.Num()
+   node.operand.n = 5
+   node.operand.lineno = 0
+   node.operand.col_offset = 0
+   node.lineno = 0
+   node.col_offset = 0
+
+or the more compact ::
+
+   node = _ast.UnaryOp(_ast.USub(), _ast.Num(5, lineno=0, col_offset=0),
+                       lineno=0, col_offset=0)
+
+
+
+Abstract Grammar
+----------------
+
+The module defines a string constant ``__version__`` which is the decimal
+subversion revision number of the file shown below.
+
+The abstract grammar is currently defined as follows:
+
+.. literalinclude:: ../../Parser/Python.asdl
diff --git a/Doc/library/language.rst b/Doc/library/language.rst
index bcf9ac0..7d6af7d 100644
--- a/Doc/library/language.rst
+++ b/Doc/library/language.rst
@@ -15,7 +15,7 @@
 .. toctree::
 
    parser.rst
-   ast.rst
+   _ast.rst
    symbol.rst
    token.rst
    keyword.rst