diff --git a/hgwebdir.cgi b/hgwebdir.cgi
--- a/hgwebdir.cgi
+++ b/hgwebdir.cgi
@@ -8,10 +8,21 @@ cgitb.enable()
 # sys.path.insert(0, "/path/to/python/lib") # if not a system-wide install
 from mercurial import hgweb
 
-# The config file looks like this:
+# The config file looks like this.  You can have paths to individual
+# repos, collections of repos in a directory tree, or both.
+#
 # [paths]
 # virtual/path = /real/path
 # virtual/path = /real/path
+#
+# [collections]
+# /prefix/to/strip/off = /root/of/tree/full/of/repos
+#
+# collections example: say directory tree /foo contains repos /foo/bar,
+# /foo/quux/baz.  Give this config section:
+#   [collections]
+#   /foo = /foo
+# Then repos will list as bar and quux/baz.
 
 # Alternatively you can pass a list of ('virtual/path', '/real/path') tuples
 # or use a dictionary with entries like 'virtual/path': '/real/path'
diff --git a/mercurial/hgweb.py b/mercurial/hgweb.py
--- a/mercurial/hgweb.py
+++ b/mercurial/hgweb.py
@@ -1075,17 +1075,27 @@ def create_server(repo):
 class hgwebdir(object):
     def __init__(self, config):
         def cleannames(items):
-            return [(name.strip('/'), path) for name, path in items]
+            return [(name.strip(os.sep), path) for name, path in items]
 
-        if type(config) == type([]):
+        if isinstance(config, (list, tuple)):
             self.repos = cleannames(config)
-        elif type(config) == type({}):
+        elif isinstance(config, dict):
             self.repos = cleannames(config.items())
             self.repos.sort()
         else:
             cp = ConfigParser.SafeConfigParser()
             cp.read(config)
-            self.repos = cleannames(cp.items("paths"))
+            self.repos = []
+            if cp.has_section('paths'):
+                self.repos.extend(cleannames(cp.items('paths')))
+            if cp.has_section('collections'):
+                for prefix, root in cp.items('collections'):
+                    for path in util.walkrepos(root):
+                        repo = os.path.normpath(path)
+                        name = repo
+                        if name.startswith(prefix):
+                            name = name[len(prefix):]
+                        self.repos.append((name.lstrip(os.sep), repo))
             self.repos.sort()
 
     def run(self, req=hgrequest()):
diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -690,3 +690,16 @@ def datestr(date=None, format='%c'):
             (time.strftime(format, time.gmtime(float(t) - tz)),
              -tz / 3600,
              ((-tz % 3600) / 60)))
+
+def walkrepos(path):
+    '''yield every hg repository under path, recursively.'''
+    def errhandler(err):
+        if err.filename == path:
+            raise err
+
+    for root, dirs, files in os.walk(path, onerror=errhandler):
+        for d in dirs:
+            if d == '.hg':
+                yield root
+                dirs[:] = []
+                break