diff --git a/tools/make_man.py b/tools/make_man.py
index 89b26c64..1b47f00b 100755
--- a/tools/make_man.py
+++ b/tools/make_man.py
@@ -118,7 +118,7 @@ def main():
                 try:
                     script = imp.load_module("scripts.%s" % fname, f, tmpfile, desc)
                 except ImportError, e:
-                    print >> sys.stderr, "Unable to load the %s script (%s)" \
+                    print >>sys.stderr, "Unable to load the %s script (%s)" \
                         % (fname, e)
                 else:
                     print "Loaded %s" % fname
diff --git a/weboob/applications/boobank/boobank.py b/weboob/applications/boobank/boobank.py
index e920c26f..528c682c 100644
--- a/weboob/applications/boobank/boobank.py
+++ b/weboob/applications/boobank/boobank.py
@@ -146,7 +146,7 @@ class Boobank(ReplApplication):
         id, backend_name = self.parse_id(id)
         if not id:
             print >>sys.stderr, 'Error: please give an account ID (hint: use list command)'
-            return 1
+            return 2
         names = (backend_name,) if backend_name is not None else None
 
         def do(backend):
@@ -204,7 +204,7 @@ class Boobank(ReplApplication):
         id_from, backend_name_from = self.parse_id(id_from)
         if not id_to:
             print >>sys.stderr, 'Error: listing recipient is not implemented yet'
-            return
+            return 4
 
         id_to, backend_name_to = self.parse_id(id_to)
 
@@ -212,11 +212,11 @@ class Boobank(ReplApplication):
             amount = float(amount)
         except (TypeError,ValueError):
             print >>sys.stderr, 'Error: please give a decimal amount to transfer'
-            return 1
+            return 2
 
         if backend_name_from != backend_name_to:
             print >>sys.stderr, "Transfer between different backends is not implemented"
-            return
+            return 4
         else:
             backend_name = backend_name_from
 
diff --git a/weboob/applications/boobathon/boobathon.py b/weboob/applications/boobathon/boobathon.py
index 10e566eb..af3f822c 100644
--- a/weboob/applications/boobathon/boobathon.py
+++ b/weboob/applications/boobathon/boobathon.py
@@ -117,7 +117,7 @@ class Event(object):
             elif line.startswith('h3=. '):
                 m = re.match('h3=. Event finished. Winner is "(.*)":/users/(\d+)\!', line)
                 if not m:
-                    print 'Unable to parse h3=: %s' % line
+                    print >>sys.stderr, 'Unable to parse h3=: %s' % line
                     continue
                 self.winner = Member(int(m.group(2)), m.group(1))
             elif line.startswith('h2. '):
@@ -125,7 +125,7 @@ class Event(object):
             elif line.startswith('h3. '):
                 m = re.match('h3. "(.*)":/users/(\d+)', line)
                 if not m:
-                    print 'Unable to parse user "%s"' % line
+                    print >>sys.stderr, 'Unable to parse user "%s"' % line
                     continue
                 member = Member(int(m.group(2)), m.group(1))
                 if member.id == self.my_id:
@@ -164,7 +164,7 @@ class Event(object):
             elif line.startswith('[['):
                 m = re.match('\[\[(\w+)\]\]\|\[\[(\w+)\]\]\|(.*)\|', line)
                 if not m:
-                    print 'Unable to parse task: "%s"' % line
+                    print >>sys.stderr, 'Unable to parse task: "%s"' % line
                     continue
                 task = Task(m.group(1), m.group(2))
                 member.tasks.append(task)
@@ -467,7 +467,8 @@ class Boobathon(ReplApplication):
                     print 'Event is now closed. Winner is %s!' % self.winner.name
                 return
 
-        print '"%s" not found' % name
+        print >>sys.stderr, '"%s" not found' % name
+        return 3
 
     def complete_edit(self, text, line, *ignored):
         args = line.split(' ')
@@ -481,8 +482,8 @@ class Boobathon(ReplApplication):
         Edit information about you or about event.
         """
         if not line:
-            print 'Syntax: edit [event | me]'
-            return
+            print >>sys.stderr, 'Syntax: edit [event | me]'
+            return 2
 
         self.event.load()
         if line == 'event':
@@ -491,12 +492,13 @@ class Boobathon(ReplApplication):
         elif line == 'me':
             mem = self.event.get_me()
             if not mem:
-                print 'You haven\'t joined the event.'
-                return
+                print >>sys.stderr, 'You haven\'t joined the event.'
+                return 1
             self.edit_member(mem)
             self.save_event('Member edited')
         else:
-            print 'Unable to edit "%s"' % line
+            print >>sys.stderr, 'Unable to edit "%s"' % line
+            return 1
 
     def do_info(self, line):
         """
@@ -552,12 +554,12 @@ class Boobathon(ReplApplication):
         """
         self.event.load()
         if self.event.backend.browser.get_userid() in self.event.members:
-            print 'You have already joined this event.'
-            return
+            print >>sys.stderr, 'You have already joined this event.'
+            return 1
 
         if self.event.is_closed():
-            print 'Boobathon is closed.'
-            return
+            print >>sys.stderr, "Boobathon is closed."
+            return 1
 
         m = Member(self.event.backend.browser.get_userid(), None)
         self.edit_member(m)
@@ -573,17 +575,18 @@ class Boobathon(ReplApplication):
         self.event.load()
 
         if self.event.currently_in_event():
-            print 'Unable to leave during the event, loser!'
-            return
+            print >>sys.stderr, 'Unable to leave during the event, loser!'
+            return 1
 
         if self.event.is_closed():
-            print 'Boobathon is closed.'
-            return
+            print >>sys.stderr, "Boobathon is closed."
+            return 1
 
         try:
             self.event.members.pop(self.event.backend.browser.get_userid())
         except KeyError:
-            print 'You have not joined this event.'
+            print >>sys.stderr, "You have not joined this event."
+            return 1
         else:
             self.save_event('Left the event')
 
@@ -596,23 +599,24 @@ class Boobathon(ReplApplication):
         self.event.load()
         mem = self.event.get_me()
         if not mem:
-            print 'You have not joined this event.'
-            return
+            print >>sys.stderr, "You have not joined this event."
+            return 1
 
         if self.event.is_closed():
-            print 'Boobathon is closed.'
-            return
+            print >>sys.stderr, "Boobathon is closed."
+            return 1
 
         try:
             task_id = int(line)
         except ValueError:
-            print 'The task ID might be a number'
-            return
+            print >>sys.stderr, 'The task ID should be a number'
+            return 2
 
         try:
             task = mem.tasks.pop(task_id)
         except IndexError:
-            print 'Unable to find task #%d' % task_id
+            print >>sys.stderr, 'Unable to find task #%d' % task_id
+            return 1
         else:
             print 'Removing task #%d (%s,%s).' % (task_id, task.backend, task.capability)
             self.save_event('Remove task')
@@ -626,25 +630,25 @@ class Boobathon(ReplApplication):
         self.event.load()
         mem = self.event.get_me()
         if not mem:
-            print 'You have not joined this event.'
-            return
+            print >>sys.stderr, "You have not joined this event."
+            return 1
 
         if self.event.is_closed():
-            print 'Boobathon is closed.'
-            return
+            print >>sys.stderr, "Boobathon is closed."
+            return 1
 
         backend, capability = self.parse_command_args(line, 2, 2)
         if not backend[0].isupper():
-            print 'The backend name "%s" needs to start with a capital.' % backend
-            return
+            print >>sys.stderr, 'The backend name "%s" needs to start with a capital.' % backend
+            return 2
         if not capability.startswith('Cap') or not capability[3].isupper():
-            print '"%s" is not a right capability name.' % capability
-            return
+            print >>sys.stderr, '"%s" is not a proper capability name (must start with Cap).' % capability
+            return 2
 
         for task in mem.tasks:
             if (task.backend,task.capability) == (backend,capability):
-                print 'A task already exists for that.'
-                return
+                print >>sys.stderr, "A task already exists for that."
+                return 1
 
         task = Task(backend, capability)
         mem.tasks.append(task)
@@ -660,16 +664,16 @@ class Boobathon(ReplApplication):
         self.event.load()
         mem = self.event.get_me()
         if not mem:
-            print 'You have not joined this event.'
-            return
+            print >>sys.stderr, "You have not joined this event."
+            return 1
 
         if len(mem.tasks) == 0:
-            print "You don't have any task to do."
-            return
+            print >>sys.stderr, "You don't have any task to do."
+            return 1
 
         if not self.event.currently_in_event():
-            print "You can't start a task, we are not in event."
-            return
+            print >>sys.stderr, "You can't start a task, we are not in event."
+            return 1
 
         if line.isdigit():
             task_id = int(line)
@@ -687,11 +691,12 @@ class Boobathon(ReplApplication):
             if (i == task_id or task_id < 0) and task.status == task.STATUS_NONE:
                 break
         else:
-            print 'Task not found.'
+            print >>sys.stderr, 'Task not found.'
+            return 3
 
         if task.status == task.STATUS_DONE:
-            print 'Task is already done.'
-            return
+            print >>sys.stderr, 'Task is already done.'
+            return 1
 
         task.status = task.STATUS_PROGRESS
         mem.tasks.remove(task)
@@ -707,12 +712,12 @@ class Boobathon(ReplApplication):
         self.event.load()
         mem = self.event.get_me()
         if not mem:
-            print 'You have not joined this event.'
-            return
+            print >>sys.stderr, "You have not joined this event."
+            return 1
 
         if self.event.is_closed():
-            print 'Boobathon is closed.'
-            return
+            print >>sys.stderr, "Boobathon is closed."
+            return 1
 
         for i, task in enumerate(mem.tasks):
             if task.status == task.STATUS_PROGRESS:
@@ -724,11 +729,13 @@ class Boobathon(ReplApplication):
                     self.save_event('Task accomplished')
                 else:
                     task.status = task.STATUS_NONE
-                    print 'Oops, you are out of event. Canceling the task...'
+                    print >>sys.stderr, 'Oops, you are out of event. Canceling the task...'
                     self.save_event('Cancel task')
+                    return 1
                 return
 
-        print "There isn't any task in progress."
+        print >>sys.stderr, "There isn't any task in progress."
+        return 1
 
     def do_cancel(self, line):
         """
@@ -739,12 +746,12 @@ class Boobathon(ReplApplication):
         self.event.load()
         mem = self.event.get_me()
         if not mem:
-            print 'You have not joined this event.'
-            return
+            print >>sys.stderr, "You have not joined this event."
+            return 1
 
         if self.event.is_closed():
-            print 'Boobathon is closed.'
-            return
+            print >>sys.stderr, "Boobathon is closed."
+            return 1
 
         for task in mem.tasks:
             if task.status == task.STATUS_PROGRESS:
@@ -753,7 +760,8 @@ class Boobathon(ReplApplication):
                 self.save_event('Cancel task')
                 return
 
-        print "There isn't any task in progress."
+        print >>sys.stderr, "There isn't any task in progress."
+        return 1
 
 
     def load_default_backends(self):
@@ -769,7 +777,7 @@ class Boobathon(ReplApplication):
                 return
 
         if not self.check_loaded_backends({'url': 'https://symlink.me'}):
-            print 'Ok, so leave now, fag.'
+            print "Ok, so leave now, fag."
             sys.exit(0)
 
     def is_backend_loadable(self, backend):
diff --git a/weboob/applications/boobmsg/boobmsg.py b/weboob/applications/boobmsg/boobmsg.py
index 633344f4..9c760649 100644
--- a/weboob/applications/boobmsg/boobmsg.py
+++ b/weboob/applications/boobmsg/boobmsg.py
@@ -342,8 +342,8 @@ class Boobmsg(ReplApplication):
         Read a message
         """
         if len(arg) == 0:
-            print 'Please give a message ID.'
-            return
+            print >>sys.stderr, 'Please give a message ID.'
+            return 2
 
         try:
             message = self.messages[int(arg) - 1]
@@ -355,6 +355,8 @@ class Boobmsg(ReplApplication):
             return
 
         if not self.interactive:
-            print 'Oops, you need to be in interactive mode to read messages'
+            print >>sys.stderr,  'Oops, you need to be in interactive mode to read messages'
+            return 1
         else:
-            print 'Message not found'
+            print >>sys.stderr,  'Message not found'
+            return 3
diff --git a/weboob/applications/galleroob/galleroob.py b/weboob/applications/galleroob/galleroob.py
index daf79b86..4b1be21d 100644
--- a/weboob/applications/galleroob/galleroob.py
+++ b/weboob/applications/galleroob/galleroob.py
@@ -102,8 +102,8 @@ class Galleroob(ReplApplication):
                 gallery = result
 
         if not gallery:
-            print 'Gallery not found: %s' % _id
-            return 1
+            print >>sys.stderr, 'Gallery not found: %s' % _id
+            return 3
 
         backend.fillobj(gallery, ('title',))
         if dest is None:
@@ -127,7 +127,7 @@ class Galleroob(ReplApplication):
             if img.data is None:
                 backend.fillobj(img, ('url','data'))
                 if img.data is None:
-                    print "Couldn't get page %d, exiting" % i
+                    print >>sys.stderr, "Couldn't get page %d, exiting" % i
                     break
 
             ext = search(r"\.([^\.]{1,5})$", img.url)
@@ -156,6 +156,6 @@ class Galleroob(ReplApplication):
         gallery = self.get_object(_id, 'get_gallery')
         if not gallery:
             print >>sys.stderr, 'Gallery not found: %s' %  _id
-            return
+            return 3
         self.format(gallery)
         self.flush()
diff --git a/weboob/applications/geolooc/geolooc.py b/weboob/applications/geolooc/geolooc.py
index 6969207b..ce979868 100644
--- a/weboob/applications/geolooc/geolooc.py
+++ b/weboob/applications/geolooc/geolooc.py
@@ -37,9 +37,7 @@ class Geolooc(ReplApplication):
     def main(self, argv):
         if len(argv) < 2:
             print >>sys.stderr, 'Syntax: %s ipaddr' % argv[0]
-            return 1
+            return 2
 
         for backend, location in self.do('get_location', argv[1]):
             self.format(location)
-
-        return 0
diff --git a/weboob/applications/havesex/havesex.py b/weboob/applications/havesex/havesex.py
index 6e2828d6..22ef0afb 100644
--- a/weboob/applications/havesex/havesex.py
+++ b/weboob/applications/havesex/havesex.py
@@ -133,7 +133,7 @@ class HaveSex(ReplApplication):
     def edit_optims(self, backend_names, optims_names, stop=False):
         if optims_names is None:
             print >>sys.stderr, 'Error: missing parameters.'
-            return 1
+            return 2
 
         for optim_name in optims_names.split():
             backends_optims = {}
@@ -165,7 +165,7 @@ class HaveSex(ReplApplication):
     def optims(self, function, backend_names, optims, store=True):
         if optims is None:
             print >>sys.stderr, 'Error: missing parameters.'
-            return 1
+            return 2
 
         for optim_name in optims.split():
             try:
@@ -211,8 +211,6 @@ class HaveSex(ReplApplication):
         if store:
             self.storage.save()
 
-        return 0
-
     def complete_optim(self, text, line, *ignored):
         args = line.split(' ')
         if len(args) == 2:
diff --git a/weboob/applications/pastoob/pastoob.py b/weboob/applications/pastoob/pastoob.py
index 8e5ca632..81c266d2 100644
--- a/weboob/applications/pastoob/pastoob.py
+++ b/weboob/applications/pastoob/pastoob.py
@@ -53,16 +53,16 @@ class Pastoob(ReplApplication):
         print args
         if not _id:
             print >>sys.stderr, 'This command takes an argument: %s' % self.get_command_help('get', short=True)
-            return 1
+            return 2
 
         try:
             paste = self.get_object(_id, 'get_paste', ['contents'])
         except PasteNotFound:
             print >>sys.stderr, 'Paste not found: %s' %  _id
-            return 2
+            return 3
         if not paste:
             print >>sys.stderr, 'Unable to handle paste: %s' %  _id
-            return 3
+            return 1
         output = codecs.getwriter(sys.stdout.encoding)(sys.stdout)
         output.write(paste.contents)
         # add a newline unless we are writing
diff --git a/weboob/applications/radioob/radioob.py b/weboob/applications/radioob/radioob.py
index 123e6725..64d67994 100644
--- a/weboob/applications/radioob/radioob.py
+++ b/weboob/applications/radioob/radioob.py
@@ -87,13 +87,13 @@ class Radioob(ReplApplication):
         Play a radio with a found player.
         """
         if not _id:
-            print 'This command takes an argument: %s' % self.get_command_help('play', short=True)
-            return
+            print >>sys.stderr, 'This command takes an argument: %s' % self.get_command_help('play', short=True)
+            return 2
 
         radio = self.get_object(_id, 'get_radio', ['streams'])
         if not radio:
             print >>sys.stderr, 'Radio not found: ' % _id
-            return
+            return 1
         try:
             player_name = self.config.get('media_player')
             if not player_name:
@@ -115,13 +115,13 @@ class Radioob(ReplApplication):
         Get information about a radio.
         """
         if not _id:
-            print 'This command takes an argument: %s' % self.get_command_help('info', short=True)
-            return
+            print >>sys.stderr, 'This command takes an argument: %s' % self.get_command_help('info', short=True)
+            return 2
 
         radio = self.get_object(_id, 'get_radio')
         if not radio:
-            print 'Radio not found:', _id
-            return
+            print >>sys.stderr, 'Radio not found:', _id
+            return 3
         self.format(radio)
         self.flush()
 
diff --git a/weboob/applications/videoob/videoob.py b/weboob/applications/videoob/videoob.py
index 7093e5ab..69ea49b6 100644
--- a/weboob/applications/videoob/videoob.py
+++ b/weboob/applications/videoob/videoob.py
@@ -93,8 +93,8 @@ class Videoob(ReplApplication):
         _id, dest = self.parse_command_args(line, 2, 1)
         video = self.get_object(_id, 'get_video', ['url'])
         if not video:
-            print 'Video not found: %s' %  _id
-            return 1
+            print >>sys.stderr, 'Video not found: %s' %  _id
+            return 3
 
         def check_exec(executable):
             with open('/dev/null', 'w') as devnull:
@@ -136,13 +136,13 @@ class Videoob(ReplApplication):
         Play a video with a found player.
         """
         if not _id:
-            print 'This command takes an argument: %s' % self.get_command_help('play', short=True)
-            return
+            print >>sys.stderr, 'This command takes an argument: %s' % self.get_command_help('play', short=True)
+            return 2
 
         video = self.get_object(_id, 'get_video', ['url'])
         if not video:
-            print 'Video not found: %s' %  _id
-            return
+            print >>sys.stderr, 'Video not found: %s' %  _id
+            return 3
         try:
             player_name = self.config.get('media_player')
             if not player_name:
@@ -164,13 +164,13 @@ class Videoob(ReplApplication):
         Get information about a video.
         """
         if not _id:
-            print 'This command takes an argument: %s' % self.get_command_help('info', short=True)
-            return
+            print >>sys.stderr, 'This command takes an argument: %s' % self.get_command_help('info', short=True)
+            return 2
 
         video = self.get_object(_id, 'get_video')
         if not video:
             print >>sys.stderr, 'Video not found: %s' %  _id
-            return
+            return 3
         self.format(video)
         self.flush()
 
@@ -193,6 +193,7 @@ class Videoob(ReplApplication):
                 self.nsfw = False
             else:
                 print 'Invalid argument "%s".' % line
+                return 2
         else:
             print "on" if self.nsfw else "off"
 
@@ -206,9 +207,9 @@ class Videoob(ReplApplication):
         """
         if len(self.enabled_backends) == 0:
             if self.interactive:
-                print 'No backend loaded. Please use the "backends" command.'
+                print >>sys.stderr, 'No backend loaded. Please use the "backends" command.'
             else:
-                print 'No backend loaded.'
+                print >>sys.stderr, 'No backend loaded.'
             return 1
 
         self.set_formatter_header(u'Search pattern: %s' % pattern if pattern else u'Latest videos')
diff --git a/weboob/applications/webcontentedit/webcontentedit.py b/weboob/applications/webcontentedit/webcontentedit.py
index d006de36..5d7c9e76 100644
--- a/weboob/applications/webcontentedit/webcontentedit.py
+++ b/weboob/applications/webcontentedit/webcontentedit.py
@@ -54,8 +54,8 @@ class WebContentEdit(ReplApplication):
             contents += [content for backend, content in self.do('get_content', _id, backends=backend_names) if content]
 
         if len(contents) == 0:
-            print >> sys.stderr, 'No contents found'
-            return 1
+            print >>sys.stderr, 'No contents found'
+            return 3
 
         paths = {}
         for content in contents:
@@ -92,8 +92,8 @@ class WebContentEdit(ReplApplication):
                 contents.remove(content)
 
         if len(contents) == 0:
-            print 'No changes. Abort.'
-            return
+            print >>sys.stderr, 'No changes. Abort.'
+            return 1
 
         print 'Contents changed:\n%s' % ('\n'.join(' * %s' % content.id for content in contents))
 
@@ -126,8 +126,8 @@ class WebContentEdit(ReplApplication):
         Display log of a page
         """
         if not line:
-            print >> sys.stderr, 'Error: please give a page ID'
-            return 1
+            print >>sys.stderr, 'Error: please give a page ID'
+            return 2
 
         _id, backend_name = self.parse_id(line)
         backend_names = (backend_name,) if backend_name is not None else self.enabled_backends
diff --git a/weboob/applications/weboobcfg/weboobcfg.py b/weboob/applications/weboobcfg/weboobcfg.py
index 4c342ae0..7994c44a 100644
--- a/weboob/applications/weboobcfg/weboobcfg.py
+++ b/weboob/applications/weboobcfg/weboobcfg.py
@@ -52,7 +52,7 @@ class WeboobCfg(ReplApplication):
         """
         if not line:
             print >>sys.stderr, 'You must specify a backend name. Hint: use the "backends" command.'
-            return
+            return 2
         name, options = self.parse_command_args(line, 2, 1)
         if options:
             options = options.split(' ')
@@ -65,8 +65,8 @@ class WeboobCfg(ReplApplication):
             try:
                 key, value = option.split('=', 1)
             except ValueError:
-                print 'Parameters have to be formatted "key=value"'
-                return
+                print >>sys.stderr, 'Parameters have to be formatted "key=value"'
+                return 2
             params[key] = value
 
         self.add_backend(name, params)
@@ -133,9 +133,8 @@ class WeboobCfg(ReplApplication):
         Remove a configured backend.
         """
         if not self.weboob.backends_config.remove_backend(instance_name):
-            print 'Backend instance "%s" does not exist' % instance_name
+            print >>sys.stderr, 'Backend instance "%s" does not exist' % instance_name
             return 1
-        return 0
 
     def do_edit(self, line):
         """
@@ -175,7 +174,7 @@ class WeboobCfg(ReplApplication):
         """
         if not line:
             print >>sys.stderr, 'You must specify a backend name. Hint: use the "backends" command.'
-            return
+            return 2
 
         try:
             backend = self.weboob.modules_loader.get_or_load_module(line)
@@ -183,7 +182,7 @@ class WeboobCfg(ReplApplication):
             backend = None
 
         if not backend:
-            print 'Backend "%s" does not exist.' % line
+            print >>sys.stderr, 'Backend "%s" does not exist.' % line
             return 1
 
         print '.------------------------------------------------------------------------------.'
diff --git a/weboob/applications/weboobcli/weboobcli.py b/weboob/applications/weboobcli/weboobcli.py
index cd8da101..ca9e64b2 100644
--- a/weboob/applications/weboobcli/weboobcli.py
+++ b/weboob/applications/weboobcli/weboobcli.py
@@ -42,7 +42,7 @@ class WeboobCli(ReplApplication):
     def main(self, argv):
         if len(argv) < 3:
             print >>sys.stderr, "Syntax: %s capability method [args ..]" % argv[0]
-            return 1
+            return 2
 
         cap_s = argv[1]
         cmd = argv[2]
diff --git a/weboob/applications/weboorrents/weboorrents.py b/weboob/applications/weboorrents/weboorrents.py
index 367ee6e0..a2741e89 100644
--- a/weboob/applications/weboorrents/weboorrents.py
+++ b/weboob/applications/weboorrents/weboorrents.py
@@ -113,6 +113,7 @@ class Weboorrents(ReplApplication):
 
         if not found:
             print >>sys.stderr, 'Torrent "%s" not found' % id
+            return 3
         else:
             self.flush()
 
@@ -149,6 +150,7 @@ class Weboorrents(ReplApplication):
                 return
 
         print >>sys.stderr, 'Torrent "%s" not found' % id
+        return 3
 
     def do_search(self, pattern):
         """
diff --git a/weboob/tools/application/base.py b/weboob/tools/application/base.py
index 4f47a59c..b63f04c8 100644
--- a/weboob/tools/application/base.py
+++ b/weboob/tools/application/base.py
@@ -304,7 +304,7 @@ class BaseApplication(object):
 
         if self.options.save_responses:
             responses_dirname = tempfile.mkdtemp(prefix='weboob_session_')
-            print 'Debug data will be saved in this directory: %s' % responses_dirname
+            print >>sys.stderr, 'Debug data will be saved in this directory: %s' % responses_dirname
             from weboob.tools.browser import BaseBrowser
             BaseBrowser.SAVE_RESPONSES = True
             BaseBrowser.responses_dirname = responses_dirname
@@ -359,7 +359,7 @@ class BaseApplication(object):
         try:
             app = klass()
         except BackendsConfig.WrongPermissions, e:
-            print e
+            print >>sys.stderr, e
             sys.exit(1)
 
         try:
@@ -367,12 +367,12 @@ class BaseApplication(object):
                 args = app.parse_args(args)
                 sys.exit(app.main(args))
             except KeyboardInterrupt:
-                print 'Program killed by SIGINT'
+                print >>sys.stderr, 'Program killed by SIGINT'
                 sys.exit(0)
             except EOFError:
                 sys.exit(0)
             except ConfigError, e:
-                print 'Configuration error: %s' % e
+                print >>sys.stderr, 'Configuration error: %s' % e
                 sys.exit(1)
             except CallErrors, e:
                 app.bcall_errors_handler(e)
diff --git a/weboob/tools/application/console.py b/weboob/tools/application/console.py
index e96bf2d9..5ba01c6b 100644
--- a/weboob/tools/application/console.py
+++ b/weboob/tools/application/console.py
@@ -126,7 +126,7 @@ class ConsoleApplication(BaseApplication):
             if r.isdigit():
                 i = int(r) - 1
                 if i < 0 or i >= len(backends):
-                    print 'Error: %s is not a valid choice' % r
+                    print >>sys.stderr, 'Error: %s is not a valid choice' % r
                     continue
                 name = backends[i]
                 try:
@@ -182,7 +182,7 @@ class ConsoleApplication(BaseApplication):
                     if response.isdigit():
                         i = int(response) - 1
                         if i < 0 or i >= len(backends):
-                            print 'Error: %s is not a valid choice' % response
+                            print >>sys.stderr, 'Error: %s is not a valid choice' % response
                             continue
                         backend_name = backends[i][0]
             else:
@@ -208,12 +208,12 @@ class ConsoleApplication(BaseApplication):
             backend = None
 
         if not backend:
-            print 'Backend "%s" does not exist.' % name
-            return None
+            print >>sys.stderr, 'Backend "%s" does not exist.' % name
+            return 1
 
         if not backend.has_caps(ICapAccount) or backend.klass.ACCOUNT_REGISTER_PROPERTIES is None:
-            print 'You can\'t register a new account with %s' % name
-            return None
+            print >>sys.stderr, 'You can\'t register a new account with %s' % name
+            return 1
 
         account = Account()
         account.properties = {}
@@ -274,8 +274,8 @@ class ConsoleApplication(BaseApplication):
             items.update(params)
             params = items
         if not backend:
-            print 'Backend "%s" does not exist. Hint: use the "backends" command.' % name
-            return None
+            print >>sys.stderr, 'Backend "%s" does not exist. Hint: use the "backends" command.' % name
+            return 1
 
         # ask for params non-specified on command-line arguments
         asked_config = False
@@ -296,7 +296,7 @@ class ConsoleApplication(BaseApplication):
             print 'Backend "%s" successfully %s.' % (name, 'updated' if edit else 'added')
             return name
         except BackendAlreadyExists:
-            print 'Backend "%s" is already configured in file "%s"' % (name, self.weboob.backends_config.confpath)
+            print >>sys.stderr, 'Backend "%s" is already configured in file "%s"' % (name, self.weboob.backends_config.confpath)
             while self.ask('Add new instance of "%s" backend?' % name, default=False):
                 new_name = self.ask('Please give new instance name (could be "%s_1")' % name, regexp=r'^[\w\-_]+$')
                 try:
@@ -304,7 +304,8 @@ class ConsoleApplication(BaseApplication):
                     print 'Backend "%s" successfully added.' % new_name
                     return new_name
                 except BackendAlreadyExists:
-                    print 'Instance "%s" already exists for backend "%s".' % (new_name, name)
+                    print >>sys.stderr, 'Instance "%s" already exists for backend "%s".' % (new_name, name)
+                    return 1
 
     def ask(self, question, default=None, masked=False, regexp=None, choices=None):
         """
@@ -396,7 +397,7 @@ class ConsoleApplication(BaseApplication):
             try:
                 v.set_value(line)
             except ValueError, e:
-                print 'Error: %s' % e
+                print >>sys.stderr, 'Error: %s' % e
             else:
                 break
 
diff --git a/weboob/tools/application/repl.py b/weboob/tools/application/repl.py
index 0433d93a..100e67d3 100644
--- a/weboob/tools/application/repl.py
+++ b/weboob/tools/application/repl.py
@@ -298,7 +298,8 @@ class ReplApplication(Cmd, ConsoleApplication):
         pass
 
     def default(self, line):
-        print 'Unknown command: "%s"' % line
+        print >>sys.stderr, 'Unknown command: "%s"' % line
+        return 2
 
     def completenames(self, text, *ignored):
         return [name for name in Cmd.completenames(self, text, *ignored) if name not in self.hidden_commands]
@@ -440,11 +441,12 @@ class ReplApplication(Cmd, ConsoleApplication):
                 else:
                     self.stdout.write('%s\n' % command_help)
             else:
-                print 'Unknown command: "%s"' % arg
+                print >>sys.stderr, 'Unknown command: "%s"' % arg
         else:
             cmds = self._parser.formatter.format_commands(self._parser.commands)
             self.stdout.write('%s\n' % cmds)
             self.stdout.write('Type "help <command>" for more info about a command.\n')
+        return 2
 
     def complete_backends(self, text, line, begidx, endidx):
         choices = []
@@ -518,7 +520,7 @@ class ReplApplication(Cmd, ConsoleApplication):
         if action in ('enable', 'disable', 'only', 'add', 'register', 'edit', 'remove'):
             if not given_backend_names:
                 print >>sys.stderr, 'Please give at least a backend name.'
-                return
+                return 2
 
         given_backends = set(backend for backend in self.weboob.iter_backends() if backend.name in given_backend_names)
 
@@ -530,7 +532,7 @@ class ReplApplication(Cmd, ConsoleApplication):
                 try:
                     self.enabled_backends.remove(backend)
                 except KeyError:
-                    print '%s is not enabled' % backend.name
+                    print >>sys.stderr, '%s is not enabled' % backend.name
         elif action == 'only':
             self.enabled_backends = set()
             for backend in given_backends:
@@ -564,11 +566,11 @@ class ReplApplication(Cmd, ConsoleApplication):
                 self.weboob.backends_config.remove_backend(backend.name)
                 self.unload_backends(backend.name)
         else:
-            print 'Unknown action: "%s"' % action
+            print >>sys.stderr, 'Unknown action: "%s"' % action
             return 1
 
         if len(self.enabled_backends) == 0:
-            print 'Warning: no more backends are loaded. %s is probably unusable.' % self.APPNAME.capitalize()
+            print >>sys.stderr, 'Warning: no more backends are loaded. %s is probably unusable.' % self.APPNAME.capitalize()
 
     def complete_logging(self, text, line, begidx, endidx):
         levels = ('debug', 'info', 'warning', 'error', 'quiet', 'default')
@@ -611,6 +613,7 @@ class ReplApplication(Cmd, ConsoleApplication):
         except KeyError:
             print >>sys.stderr, 'Level "%s" does not exist.' % args[0]
             print >>sys.stderr, 'Availables: %s' % ' '.join(levels.iterkeys())
+            return 2
         else:
             logging.root.setLevel(level)
             for handler in logging.root.handlers:
@@ -634,6 +637,7 @@ class ReplApplication(Cmd, ConsoleApplication):
                     self.condition = ResultsCondition(line)
                 except ResultsConditionError, e:
                     print >>sys.stderr, '%s' % e
+                    return 2
         else:
             if self.condition is None:
                 print 'No condition is set.'
@@ -658,12 +662,14 @@ class ReplApplication(Cmd, ConsoleApplication):
                 try:
                     count = int(line)
                 except ValueError:
-                    print 'Could not interpret "%s" as a number.' % line
+                    print >>sys.stderr, 'Could not interpret "%s" as a number.' % line
+                    return 2
                 else:
                     if count > 0:
                         self.options.count = count
                     else:
-                        print 'Number must be at least 1.'
+                        print >>sys.stderr, 'Number must be at least 1.'
+                        return 2
         else:
             if self.options.count is None:
                 print 'Counting disabled.'
@@ -717,14 +723,16 @@ class ReplApplication(Cmd, ConsoleApplication):
                             print 'off' if self.options.no_keys else 'on'
                     else:
                         if args[2] not in ('on', 'off'):
-                            print 'Invalid value "%s". Please use "on" or "off" values.' % args[2]
+                            print >>sys.stderr, 'Invalid value "%s". Please use "on" or "off" values.' % args[2]
+                            return 2
                         else:
                             if args[1] == 'header':
                                 self.options.no_header = True if args[2] == 'off' else False
                             elif args[1] == 'keys':
                                 self.options.no_keys = True if args[2] == 'off' else False
                 else:
-                    print 'Don\'t know which option to set. Available options: header, keys.'
+                    print >>sys.stderr, 'Don\'t know which option to set. Available options: header, keys.'
+                    return 2
             else:
                 if args[0] in self.formatters_loader.get_available_formatters():
                     if len(args) > 1:
@@ -733,8 +741,9 @@ class ReplApplication(Cmd, ConsoleApplication):
                         self.commands_formatters = {}
                         self.DEFAULT_FORMATTER = self.set_formatter(args[0])
                 else:
-                    print 'Formatter "%s" is not available.\n' \
+                    print >>sys.stderr, 'Formatter "%s" is not available.\n' \
                             'Available formatters: %s.' % (args[0], ', '.join(self.formatters_loader.get_available_formatters()))
+                    return 1
         else:
             print 'Default formatter: %s' % self.DEFAULT_FORMATTER
             for key, klass in self.commands_formatters.iteritems():
@@ -779,16 +788,16 @@ class ReplApplication(Cmd, ConsoleApplication):
         else:
             backend_name = line.strip()
             if not backend_name:
-                print 'Please specify a backend name.'
-                return
+                print >>sys.stderr, 'Please specify a backend name.'
+                return 2
             backends = set(backend for backend in self.enabled_backends if backend.name == backend_name)
             if not backends:
-                print 'No backend found for "%s"' % backend_name
-                return
+                print >>sys.stderr, 'No backend found for "%s"' % backend_name
+                return 1
             backend = backends.pop()
         if not hasattr(backend, '_browser'):
-            print 'No browser created for backend "%s" yet. Please invoke a command before.' % backend.name
-            return
+            print >>sys.stderr, 'No browser created for backend "%s" yet. Please invoke a command before.' % backend.name
+            return 1
         browser = backend._browser
         data = browser.parser.tostring(browser.page.document)
         try:
@@ -866,10 +875,10 @@ class ReplApplication(Cmd, ConsoleApplication):
         try:
             self.formatter = self.formatters_loader.build_formatter(name)
         except FormatterLoadError, e:
-            print '%s' % e
+            print >>sys.stderr, '%s' % e
             if self.DEFAULT_FORMATTER == name:
                 self.DEFAULT_FORMATTER = ReplApplication.DEFAULT_FORMATTER
-            print 'Falling back to "%s".' % (self.DEFAULT_FORMATTER)
+            print >>sys.stderr, 'Falling back to "%s".' % (self.DEFAULT_FORMATTER)
             self.formatter = self.formatters_loader.build_formatter(self.DEFAULT_FORMATTER)
             name = self.DEFAULT_FORMATTER
         if self.options.no_header:
@@ -892,9 +901,9 @@ class ReplApplication(Cmd, ConsoleApplication):
         try:
             self.formatter.format(obj=result, selected_fields=fields)
         except FieldNotFound, e:
-            print e
+            print >>sys.stderr, e
         except MandatoryFieldsNotFound, e:
-            print >> sys.stderr, '%s Hint: select missing fields or use another formatter (ex: multiline).' % e
+            print >>sys.stderr, '%s Hint: select missing fields or use another formatter (ex: multiline).' % e
 
     def flush(self):
         self.formatter.flush()
diff --git a/weboob/tools/browser/browser.py b/weboob/tools/browser/browser.py
index 3c380ac8..fa11b06e 100644
--- a/weboob/tools/browser/browser.py
+++ b/weboob/tools/browser/browser.py
@@ -24,6 +24,7 @@ from httplib import BadStatusLine
 from logging import warning
 import mechanize
 import os
+import sys
 import re
 import tempfile
 from threading import RLock
@@ -316,7 +317,7 @@ class BaseBrowser(mechanize.Browser):
         """
         if self.responses_dirname is None:
             self.responses_dirname = tempfile.mkdtemp(prefix='weboob_session_')
-            print 'Debug data will be saved in this directory: %s' % self.responses_dirname
+            print >>sys.stderr, 'Debug data will be saved in this directory: %s' % self.responses_dirname
         response_filepath = os.path.join(self.responses_dirname, unicode(self.responses_count))
         with open(response_filepath, 'w') as f:
             f.write(result.read())
@@ -513,7 +514,7 @@ class BaseBrowser(mechanize.Browser):
                                 value = [self.str(is_list.index(args[label]))]
                             except ValueError, e:
                                 if args[label]:
-                                    print '[%s] %s: %s' % (label, args[label], e)
+                                    print >>sys.stderr, '[%s] %s: %s' % (label, args[label], e)
                                 return
                         else:
                             value = [self.str(args[label])]