diff --git a/linkcheck/checker/cache.py b/linkcheck/checker/cache.py
index 1a15ac27..b928992a 100644
--- a/linkcheck/checker/cache.py
+++ b/linkcheck/checker/cache.py
@@ -79,6 +79,9 @@ class Cache (object):
         self.pool = linkcheck.checker.pool.ConnectionPool()
 
     def incoming_is_empty (self):
+        """
+        Check if incoming queue is empty.
+        """
         self.lock.acquire()
         try:
             return len(self.incoming) <= 0
@@ -144,6 +147,12 @@ class Cache (object):
             self.lock.release()
 
     def has_incoming (self, key):
+        """
+        Check if incoming queue has an entry with the given key.
+
+        @param key: Usually obtained from url_data.cache_url_key
+        @type key: String
+        """
         self.lock.acquire()
         try:
             return key in self.incoming
@@ -151,6 +160,12 @@ class Cache (object):
             self.lock.release()
 
     def has_in_progress (self, key):
+        """
+        Check if in-progress queue has an entry with the given key.
+
+        @param key: Usually obtained from url_data.cache_url_key
+        @type key: String
+        """
         self.lock.acquire()
         try:
             return key in self.in_progress
@@ -158,7 +173,9 @@ class Cache (object):
             self.lock.release()
 
     def in_progress_remove (self, url_data):
-        """remove url from in-progress cache"""
+        """
+        Remove url from in-progress cache.
+        """
         self.lock.acquire()
         try:
             key = url_data.cache_url_key
@@ -168,7 +185,9 @@ class Cache (object):
             self.lock.release()
 
     def checked_add (self, url_data):
-        """cache checked url data"""
+        """
+        Cache checked url data.
+        """
         self.lock.acquire()
         try:
             data = url_data.get_cache_data()
diff --git a/linkcheck/checker/ftpurl.py b/linkcheck/checker/ftpurl.py
index ee52b070..b7b5f3d3 100644
--- a/linkcheck/checker/ftpurl.py
+++ b/linkcheck/checker/ftpurl.py
@@ -40,6 +40,9 @@ class FtpUrl (urlbase.UrlBase, proxysupport.ProxySupport):
     def __init__ (self, base_url, recursion_level, consumer,
                   parent_url = None,
                   base_ref = None, line=0, column=0, name=u""):
+        """
+        Initialize FTP url data.
+        """
         super(FtpUrl, self).__init__(base_url, recursion_level, consumer,
              parent_url=parent_url, base_ref=base_ref,
              line=line, column=column, name=name)
@@ -155,6 +158,9 @@ class FtpUrl (urlbase.UrlBase, proxysupport.ProxySupport):
         """
         files = []
         def add_entry (line):
+            """
+            Parse list line and add the entry it points to to the file list.
+            """
             linkcheck.log.debug(linkcheck.LOG_CHECK, "Directory entry %r",
                                 line)
             try:
diff --git a/linkcheck/checker/proxysupport.py b/linkcheck/checker/proxysupport.py
index cea3233f..73f13aeb 100644
--- a/linkcheck/checker/proxysupport.py
+++ b/linkcheck/checker/proxysupport.py
@@ -56,6 +56,9 @@ class ProxySupport (object):
 
 
     def ignore_proxy_host (self):
+        """
+        Check if self.host is in the no-proxy-for ignore list.
+        """
         for ro in self.consumer.config["noproxyfor"]:
             if ro.search(self.host):
                 return True
diff --git a/linkcheck/checker/urlbase.py b/linkcheck/checker/urlbase.py
index fae2e84c..d8527544 100644
--- a/linkcheck/checker/urlbase.py
+++ b/linkcheck/checker/urlbase.py
@@ -82,6 +82,11 @@ def print_app_info ():
 
 
 def urljoin (parent, url, scheme):
+    """
+    If url is relative, join parent and url. Else leave url as-is.
+
+    @return join url
+    """
     if url.startswith(scheme+":"):
         return url
     return urlparse.urljoin(parent, url)
diff --git a/linkcheck/configuration.py b/linkcheck/configuration.py
index f899c0a9..e87f52de 100644
--- a/linkcheck/configuration.py
+++ b/linkcheck/configuration.py
@@ -150,6 +150,10 @@ class Configuration (dict):
         self.init_geoip()
 
     def init_geoip (self):
+        """
+        If GeoIP.dat file is found, initialize a standard geoip DB and
+        store it in self["geoip"]; else this value will be None.
+        """
         geoip_dat = "/usr/share/GeoIP/GeoIP.dat"
         if _has_geoip and os.path.exists(geoip_dat):
             self["geoip"] = GeoIP.open(geoip_dat, GeoIP.GEOIP_STANDARD)
@@ -332,7 +336,8 @@ class Configuration (dict):
         except ConfigParser.Error, msg:
             linkcheck.log.debug(linkcheck.LOG_CHECK, msg)
         try:
-            self["externstrictall"] = cfgparser.getboolean(section, "externstrictall")
+            self["externstrictall"] = \
+                          cfgparser.getboolean(section, "externstrictall")
         except ConfigParser.Error, msg:
             linkcheck.log.debug(linkcheck.LOG_CHECK, msg)
         try:
diff --git a/linkcheck/containers.py b/linkcheck/containers.py
index 76be0044..8ae0f71a 100644
--- a/linkcheck/containers.py
+++ b/linkcheck/containers.py
@@ -73,6 +73,7 @@ class ListDict (dict):
         """
         Initialize sorted key list.
         """
+        super(ListDict, self).__init__()
         # sorted list of keys
         self._keys = []
 
diff --git a/linkcheck/fcgi.py b/linkcheck/fcgi.py
index e3537fa2..f1b73828 100644
--- a/linkcheck/fcgi.py
+++ b/linkcheck/fcgi.py
@@ -122,7 +122,7 @@ class Record (object):
             data = sock.recv(content_length - len(self.content))
             self.content += data
         if padding_length != 0:
-            _padding = sock.recv(padding_length)
+            sock.recv(padding_length)
 
         # Parse the content information
         c = self.content
@@ -220,12 +220,13 @@ def HandleManTypes (r, conn):
     if r.rec_type == FCGI_GET_VALUES:
         r.rec_type = FCGI_GET_VALUES_RESULT
         v = {}
-        vars = {'FCGI_MAX_CONNS' : FCGI_MAX_CONNS,
+        _vars = {'FCGI_MAX_CONNS' : FCGI_MAX_CONNS,
                 'FCGI_MAX_REQS'  : FCGI_MAX_REQS,
                 'FCGI_MPXS_CONNS': FCGI_MPXS_CONNS}
         for i in r.values.keys():
-            if vars.has_key(i): v[i]=vars[i]
-        r.values = vars
+            if _vars.has_key(i):
+                v[i] = _vars[i]
+        r.values = _vars
         r.write_record(conn)
 
 
@@ -334,7 +335,6 @@ class FastCGIWriter (object):
 _isFCGI = 1         # assume it is until we find out for sure
 
 def isFCGI ():
-    global _isFCGI
     return _isFCGI
 
 
@@ -469,8 +469,8 @@ def _startup ():
         s = socket.fromfd(sys.stdin.fileno(), socket.AF_INET,
                           socket.SOCK_STREAM)
         s.getpeername()
-    except socket.error, (err, errmsg):
-        if err != errno.ENOTCONN:   # must be a non-fastCGI environment
+    except socket.error, msg:
+        if msg[0] != errno.ENOTCONN:   # must be a non-fastCGI environment
             global _isFCGI
             _isFCGI = 0
             return
diff --git a/linkcheck/lc_cgi.py b/linkcheck/lc_cgi.py
index 56e5a97d..8f743cd7 100644
--- a/linkcheck/lc_cgi.py
+++ b/linkcheck/lc_cgi.py
@@ -30,6 +30,9 @@ import linkcheck.configuration
 import linkcheck.url
 import linkcheck.i18n
 import linkcheck.strformat
+import linkcheck.checker
+import linkcheck.checker.cache
+import linkcheck.checker.consumer
 
 _logfile = None
 _supported_langs = ('de', 'fr', 'nl', 'C')
@@ -98,9 +101,6 @@ def checklink (out=sys.stdout, form=None, env=os.environ):
     config["externlinks"].append(
              linkcheck.get_link_pat("^%s$" % linkcheck.url.safe_url_pattern))
     config["externlinks"].append(linkcheck.get_link_pat(".*", strict=True))
-    import linkcheck.checker
-    import linkcheck.checker.cache
-    import linkcheck.checker.consumer
     cache = linkcheck.checker.cache.Cache()
     consumer = linkcheck.checker.consumer.Consumer(config, cache)
     # start checking
diff --git a/linkcheck/logger/dot.py b/linkcheck/logger/dot.py
index da5bf357..64b2c7a0 100644
--- a/linkcheck/logger/dot.py
+++ b/linkcheck/logger/dot.py
@@ -127,10 +127,16 @@ class DOTLogger (linkcheck.logger.Logger):
 
 
 def dotquote (s):
+    """
+    Escape disallowed characters in DOT format strings.
+    """
     return s.replace('"', '\\"')
 
 
 def dotedge (s):
+    """
+    Escape disallowed characters in DOT edge labels.
+    """
     s = s.replace("\n", "\\n")
     s = s.replace("\r", "\\r")
     s = s.replace("\l", "\\l")
diff --git a/linkcheck/logger/html.py b/linkcheck/logger/html.py
index 19fce548..a684df3d 100644
--- a/linkcheck/logger/html.py
+++ b/linkcheck/logger/html.py
@@ -272,7 +272,7 @@ class HtmlLogger (linkcheck.logger.Logger):
            self.field("result")+u"</td><td bgcolor=\""+self.colorerror+u"\">")
             self.write(_("Error"))
         if url_data.result:
-              self.write(u": "+cgi.escape(url_data.result))
+            self.write(u": "+cgi.escape(url_data.result))
         self.writeln(u"</td></tr>")
 
     def end_output (self, linknumber=-1):
diff --git a/linkcheck/msgfmt.py b/linkcheck/msgfmt.py
index 34f72fc9..ba43c2b5 100644
--- a/linkcheck/msgfmt.py
+++ b/linkcheck/msgfmt.py
@@ -37,11 +37,14 @@ __version__ = "1.1"
 MESSAGES = {}
 
 
-def usage (code, msg=''):
+def usage (ecode, msg=''):
+    """
+    Print usage and msg and exit with given code.
+    """
     print >> sys.stderr, __doc__
     if msg:
         print >> sys.stderr, msg
-    sys.exit(code)
+    sys.exit(ecode)
 
 
 def add (msgid, transtr, fuzzy):
@@ -54,19 +57,21 @@ def add (msgid, transtr, fuzzy):
 
 
 def generate ():
-    "Return the generated output."
+    """
+    Return the generated output.
+    """
     global MESSAGES
     keys = MESSAGES.keys()
     # the keys are sorted in the .mo file
     keys.sort()
     offsets = []
     ids = strs = ''
-    for id in keys:
+    for _id in keys:
         # For each string, we need size and file offset.  Each string is NUL
         # terminated; the NUL does not count into the size.
-        offsets.append((len(ids), len(id), len(strs), len(MESSAGES[id])))
-        ids += id + '\0'
-        strs += MESSAGES[id] + '\0'
+        offsets.append((len(ids), len(_id), len(strs), len(MESSAGES[_id])))
+        ids += _id + '\0'
+        strs += MESSAGES[_id] + '\0'
     output = ''
     # The header is 7 32-bit unsigned integers.  We don't use hash tables, so
     # the keys start right after the index tables.
@@ -119,6 +124,7 @@ def make (filename, outfile):
     fuzzy = 0
 
     # Parse the catalog
+    msgid = msgstr = ''
     lno = 0
     for l in lines:
         lno += 1