diff --git a/manual/source/classes/base_classes/Makefile b/manual/source/classes/base_classes/Makefile
index eb3fd68a9..75914a8f2 100644
--- a/manual/source/classes/base_classes/Makefile
+++ b/manual/source/classes/base_classes/Makefile
@@ -40,6 +40,9 @@ all :: $(RSTs) $(TARGET_NXDLs)
 %.nxdl.xml : $(SRCDIR)/%.$(NXDL_SUFFIX)  Makefile
 	cp $(SRCDIR)/$@   ./$@
 
+index.rst: $(ROOTDIR)/utils/nxdl_summary.py $(SRCDIR)/*.nxdl.xml
+	python $(ROOTDIR)/utils/nxdl_summary.py base_classes
+
 %.rst : %.$(NXDL_SUFFIX) $(NXDL2RST) Makefile
 	python $(NXDL2RST) $< > $@
 
diff --git a/utils/nxdl_summary.py b/utils/nxdl_summary.py
new file mode 100755
index 000000000..42db7d2b9
--- /dev/null
+++ b/utils/nxdl_summary.py
@@ -0,0 +1,111 @@
+#!/usr/bin/env python
+
+'''
+Summarize the NXDL classes definitions for the given NXDL section.
+
+Re-write the index.rst file with a list of: class  summary (and a hidden toctree)
+'''
+
+
+import os, sys
+import lxml.etree
+
+
+TITLE_MARKERS = '- + ~ ^ * @'.split()  # used for underscoring section titles
+INDENTATION = ' '*4
+
+
+NAMESPACE = 'http://definition.nexusformat.org/nxdl/3.1'
+NS = {'nx': NAMESPACE}
+
+
+PREAMBLES = {
+    'base_classes': '''
+.. index::
+     ! see: class definitions; base class
+     ! base class
+
+.. _base.class.definitions:
+
+Base Class Definitions
+######################
+
+A description of each NeXus base class definition is given.
+NeXus base class definitions define the set of terms that
+*might* be used in an instance of that class.
+Consider the base classes as a set of *components*
+that are used to construct a data file.
+    ''',
+
+    'applications': '''
+    ''',
+    
+    'contributed_definitions': '''
+    ''',
+}
+
+
+def getSummary(nxdl_file):
+    tree = lxml.etree.parse(nxdl_file)
+    root = tree.getroot()
+    nodes = root.xpath('nx:doc', namespaces=NS)
+    if len(nodes) != 1:
+        raise RuntimeError('wrong number of <doc> nodes in NXDL: ' + nxdl_file)
+    text = nodes[0].text
+    return text.strip().splitlines()[0]
+
+
+def command_args():
+    '''get the command-line arguments, handle syntax errors'''
+    import argparse
+    doc = __doc__.strip().splitlines()[0]
+    parser = argparse.ArgumentParser(prog=sys.argv[0], description=doc)
+    parser.add_argument('section',
+                        action='store', 
+                        help="NXDL section (such as *base_classes*)")
+    return parser.parse_args()
+
+
+def main(section):
+    if section not in PREAMBLES.keys():
+        raise KeyError('unknown NXDL section: ' + section)
+    base_path = os.path.abspath(os.path.dirname(__file__))
+    nxdl_path = os.path.abspath(os.path.join(base_path, '..', section))
+    if not os.path.exists(nxdl_path):
+        raise IOError('not found: ' + nxdl_path)
+
+    rst_path = os.path.abspath(os.path.join(base_path, '..', 'manual', 'source', 'classes', section))
+    if not os.path.exists(rst_path):
+        raise IOError('not found: ' + rst_path)
+
+    index_file = os.path.join(rst_path, 'index.rst')
+
+    classes = []
+    text = []
+    text.append('''
+.. do NOT edit this file
+   automatically generated by script ''' + __file__)
+    text.append('')
+    text.append(PREAMBLES[section])
+    for fname in sorted(os.listdir(nxdl_path)):
+        if fname.endswith('.nxdl.xml'):
+            class_name = fname.split('.')[0]
+            classes.append(class_name)
+            summary = getSummary(os.path.join(nxdl_path, fname))
+            text.append('')
+            text.append(':ref:`' + class_name + '`')
+            text.append(INDENTATION + summary)
+    text.append('')
+    text.append('.. toctree::')
+    text.append(INDENTATION + ':hidden:')
+    text.append('')
+    for cname in sorted(classes):
+        text.append(INDENTATION + cname)
+    text.append('')
+    open(index_file, 'w').writelines('\n'.join(text))
+
+
+if __name__ == '__main__':
+    sys.argv.append('base_classes')
+    cli = command_args()
+    main(cli.section)