diff --git a/plugin/README.txt b/plugin/README.txt
new file mode 100644
index 0000000..fa4ddd5
--- /dev/null
+++ b/plugin/README.txt
@@ -0,0 +1,105 @@
+=======================
+Dynamic Plug-in Modules
+=======================
+
+  ($Id$)
+
+  >>> import os
+  >>> basePath = os.path.join(os.path.dirname(__file__), 'testing')
+
+Let's first create a module with a function we'll call later.
+
+  >>> mod1Path = os.path.join(basePath, 'mod1.py')
+  >>> src = '''
+  ... from cybertools.plugin.base import register
+  ...
+  ... @register()
+  ... def show():
+  ...     print 'mod1.show() executed'
+  ... '''
+  >>> f = open(mod1Path, 'w')
+  >>> f.write(src)
+  >>> f.close()
+
+We could import this module now but in order to be able to automatically
+reload it later (and be able to look it up in the plug-in module registry)
+we use a loader module.
+
+  >>> loadPath = os.path.join(basePath, 'load.py')
+  >>> src = '''
+  ... from cybertools.plugin.manage import loadModules
+  ...
+  ... from cybertools.plugin.testing import mod1
+  ... loadModules(mod1)
+  ...
+  ... '''
+  >>> f = open(loadPath, 'w')
+  >>> f.write(src)
+  >>> f.close()
+
+Now we first import the load module, then import the test module and call
+the function in it.
+
+  >>> from cybertools.plugin.testing import load
+
+  >>> from cybertools.plugin.testing import mod1
+  >>> mod1.show()
+  mod1.show() executed
+
+We now append additional code to mod1 and see if it is reloaded automatically;
+in order to create a sufficient time difference we change the stored setting.
+We also have to remove the .pyc file, otherwise Python will refuse to
+recompile the source file because the modification time is not changed
+during the run of the test script.
+
+  >>> from cybertools.plugin.manage import modules
+  >>> modules['cybertools.plugin.testing.mod1'].timeStamp -= 2
+  >>> os.remove(os.path.join(basePath, 'mod1.pyc'))
+
+  >>> src = '''    print 'now changed...'
+  ...
+  ... '''
+  >>> f = open(mod1Path, 'a')
+  >>> f.write(src)
+  >>> f.close()
+
+  >>> mod1.show()
+  mod1.show() executed
+  now changed...
+
+We now append another function to the source file.
+
+  >>> src = '''
+  ... @register()
+  ... def another():
+  ...     print 'executing another function.'
+  ...
+  ... '''
+  >>> f = open(mod1Path, 'a')
+  >>> f.write(src)
+  >>> f.close()
+
+  >>> modules['cybertools.plugin.testing.mod1'].timeStamp -= 2
+  >>> os.remove(os.path.join(basePath, 'mod1.pyc'))
+
+When we now try to call the new function, the module will not be reloaded
+automatically.
+
+  >>> mod1.another()
+  Traceback (most recent call last):
+  ...
+  AttributeError: 'module' object has no attribute 'another'
+
+But just reloading the load module will also update the mod1 application module.
+
+  >>> reload(load)
+  <module 'cybertools.plugin.testing.load' ...>
+  >>> mod1.another()
+  executing another function.
+
+Fin de partie
+=============
+
+  >>> for fn in ('mod1', 'load'):
+  ...     os.remove(os.path.join(basePath, fn) + '.py')
+  ...     os.remove(os.path.join(basePath, fn) + '.pyc')
diff --git a/plugin/__init__.py b/plugin/__init__.py
new file mode 100644
index 0000000..38314f3
--- /dev/null
+++ b/plugin/__init__.py
@@ -0,0 +1,3 @@
+"""
+$Id$
+"""
diff --git a/plugin/base.py b/plugin/base.py
new file mode 100644
index 0000000..cb00859
--- /dev/null
+++ b/plugin/base.py
@@ -0,0 +1,49 @@
+#
+#  Copyright (c) 2009 Helmut Merz helmutm@cy55.de
+#
+#  This program is free software; you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation; either version 2 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software
+#  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+
+"""
+Basic plug-in functionality.
+
+$Id$
+"""
+
+from cybertools.plugin.manage import checkReload, registerFunction
+
+
+def register(*ifc):
+
+    def _register(fct):
+
+        def _fct(*args, **kw):
+            fctNew = checkReloadFunction(fct)
+            if fctNew is None:
+                raise ValueError('Function no longer present: %s.%s' %
+                                    fct.__module__, fct.__name__)
+            return fctNew(*args, **kw)
+
+        registerFunction(_fct, fct, ifc)
+        return _fct
+
+    return _register
+
+
+def checkReloadFunction(f):
+    m = checkReload(f.__module__)
+    if m:
+        return getattr(m, f.__name__, None)
+    return f
diff --git a/plugin/manage.py b/plugin/manage.py
new file mode 100644
index 0000000..60e5b2a
--- /dev/null
+++ b/plugin/manage.py
@@ -0,0 +1,87 @@
+#
+#  Copyright (c) 2009 Helmut Merz helmutm@cy55.de
+#
+#  This program is free software; you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation; either version 2 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software
+#  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+
+"""
+Plug-in management.
+
+$Id$
+"""
+
+import os, sys, time
+from zope import component
+
+
+class PluginModule(object):
+
+    def __init__(self, module):
+        self.name = module.__name__
+        self.module = module
+        self.timeStamp = time.time()
+        self.functions = dict()
+        self.interfaces = dict()
+
+    def registerFunction(self, f, name, ifc):
+        self.functions[name] = f
+        self.interfaces[name] = ifc
+
+
+modules = dict()
+
+
+def registerModule(m):
+    pm = PluginModule(m)
+    modules[m.__name__] = pm
+    return pm
+
+
+def registerFunction(wrapped, base, ifc):
+    m = sys.modules[base.__module__]
+    pm = modules.get(m.__name__)
+    if pm:
+        if base.__name__ in pm.functions:
+            ifcOld = pm.interfaces[base.__name__]
+            if ifcOld:
+                gsm = component.getGlobalSiteManager()
+                gsm.unregisterHandler(pm.functions[base.__name__], ifcOld)
+    if pm is None or pm.module != m:
+        pm = registerModule(m)
+    pm.registerFunction(wrapped, base.__name__, ifc)
+    if ifc:
+        component.provideHandler(wrapped, ifc)
+
+
+# automatic reloading
+
+def checkReload(m):
+    if isinstance(m, str):
+        m = sys.modules[m]
+    fpath, ext = os.path.splitext(os.path.abspath(m.__file__))
+    src = fpath + '.py'
+    pm = modules[m.__name__]
+    mtime = pm.timeStamp
+    if os.path.getmtime(src) > mtime:
+        m = reload(m)
+        pm.timeStamp = time.time()
+        return m
+    return False
+
+
+def loadModules(*mods):
+    for m in mods:
+        checkReload(m)
+
diff --git a/plugin/testing/__init__.py b/plugin/testing/__init__.py
new file mode 100644
index 0000000..38314f3
--- /dev/null
+++ b/plugin/testing/__init__.py
@@ -0,0 +1,3 @@
+"""
+$Id$
+"""
diff --git a/plugin/tests.py b/plugin/tests.py
new file mode 100755
index 0000000..e7848c2
--- /dev/null
+++ b/plugin/tests.py
@@ -0,0 +1,28 @@
+#! /usr/bin/python
+
+"""
+Tests for the 'cybertools.plugin' package.
+
+$Id$
+"""
+
+import unittest, doctest
+from zope.testing.doctestunit import DocFileSuite
+
+
+class Test(unittest.TestCase):
+    "Basic tests for the plugin package."
+
+    def testBasicStuff(self):
+        pass
+
+
+def test_suite():
+    flags = doctest.NORMALIZE_WHITESPACE | doctest.ELLIPSIS
+    return unittest.TestSuite((
+        unittest.makeSuite(Test),
+        DocFileSuite('README.txt', optionflags=flags),
+        ))
+
+if __name__ == '__main__':
+    unittest.main(defaultTest='test_suite')