diff --git a/CHANGES b/CHANGES
index 6bcb46e72..9fc3979e0 100644
--- a/CHANGES
+++ b/CHANGES
@@ -5,11 +5,16 @@ website will have to do for older versions.
 
 = 3.2.2 (unreleased) =
 
+This release contains contributions from (alphabetically by first name):
+ - Andrius Štikonas
+ - artoo@cromnix.org
+ - Caio Carvalho
+ - Philip Müller
+ - Simon Quigley
+ - Walter Lapchynski
+
 == Core ==
 
- * Contributions from the following people (alphabetically by first name):
-   - artoo@cromnix.org
-   - Caio Carvalho
  * Example configurations are **no longer installed** by default.
    The default setting for *INSTALL_CONFIG* has changed. Distributions
    are strongly encouraged to write their own configuration files and
@@ -45,6 +50,14 @@ website will have to do for older versions.
    a bad configuration). The configuration is a little more flexible
    because a service (or target) name can be used on its own with
    sensible defaults.
+ * The displaymanager module has been entirely revamped. A long-standing
+   bug which ignored the settings for default desktop has been fixed
+   (thanks to Walter Lapchynski). Translations have been added to the
+   error messages. Each DM now has an implementation class for doing
+   all the configuration steps it needs. This groups the code needed for
+   a specific DM (and presumably, per-distro) in one place.
+   Distro's are **strongly advised** to re-test their DM configuration
+   and installation with the revamped code.
 
 **3.2.1** (2018-06-25)
 
diff --git a/ci/travis-continuous.sh b/ci/travis-continuous.sh
index 42cfb4bd3..4ac243f23 100755
--- a/ci/travis-continuous.sh
+++ b/ci/travis-continuous.sh
@@ -3,13 +3,14 @@
 # Travis CI script for use on every-commit:
 #  - build and install Calamares
 #
-test -n "$BUILDDIR" || exit 1
-test -n "$SRCDIR" || exit 1
+test -n "$BUILDDIR" || { echo "! \$BUILDDIR not set" ; exit 1 ; }
+test -n "$SRCDIR" || { echo "! \$SRCDIR not set" ; exit 1 ; }
 
-test -d $BUILDDIR || exit 1
-test -d $SRCDIR || exit 1
-test -f $SRCDIR/CMakeLists.txt || exit 1
+test -d $BUILDDIR || { echo "! $BUILDDIR not a directory" ; exit 1 ; }
+test -d $SRCDIR || { echo "! $SRCDIR not a directory" ; exit 1 ; }
+test -f $SRCDIR/CMakeLists.txt || { echo "! Missing $SRCDIR/CMakeLists.txt" ; exit 1 ; }
 
 cd $BUILDDIR || exit 1
 
+echo "# cmake $CMAKE_ARGS $SRCDIR"
 cmake $CMAKE_ARGS $SRCDIR && make -j2 && make install DESTDIR=/build/INSTALL_ROOT
diff --git a/ci/travis-coverity.sh b/ci/travis-coverity.sh
index c9495cf56..88b6a2ab5 100755
--- a/ci/travis-coverity.sh
+++ b/ci/travis-coverity.sh
@@ -3,13 +3,13 @@
 # Travis CI script for weekly (cron) use:
 #  - use the coverity tool to build and and upload results
 #
-test -n "$COVERITY_SCAN_TOKEN" || exit 1
-test -n "$BUILDDIR" || exit 1
-test -n "$SRCDIR" || exit 1
+test -n "$COVERITY_SCAN_TOKEN" || { echo "! Missing Coverity token" ; exit 1 ; }
+test -n "$BUILDDIR" || { echo "! \$BUILDDIR not set" ; exit 1 ; }
+test -n "$SRCDIR" || { echo "! \$SRCDIR not set" ; exit 1 ; }
 
-test -d $BUILDDIR || exit 1
-test -d $SRCDIR || exit 1
-test -f $SRCDIR/CMakeLists.txt || exit 1
+test -d $BUILDDIR || { echo "! $BUILDDIR not a directory" ; exit 1 ; }
+test -d $SRCDIR || { echo "! $SRCDIR not a directory" ; exit 1 ; }
+test -f $SRCDIR/CMakeLists.txt || { echo "! Missing $SRCDIR/CMakeLists.txt" ; exit 1 ; }
 
 cd $BUILDDIR || exit 1
 
@@ -20,7 +20,7 @@ mkdir "$BUILDDIR/coveritytool"
 tar xvf coverity_tool.tar.gz -C "$BUILDDIR/coveritytool" --strip-components 2
 export PATH="$BUILDDIR/coveritytool/bin:$PATH"
 
-
+echo "# cmake -DCMAKE_BUILD_TYPE=Debug $CMAKE_ARGS $SRCDIR"
 cmake -DCMAKE_BUILD_TYPE=Debug $CMAKE_ARGS $SRCDIR || exit 1
 cov-build --dir cov-int make -j2
 
diff --git a/ci/travis.sh b/ci/travis.sh
index 364923b9e..737da95d4 100755
--- a/ci/travis.sh
+++ b/ci/travis.sh
@@ -8,11 +8,11 @@
 #    intensive than the coverity add-on, but works on master.
 #
 D=`dirname "$0"`
-test -d "$D" || exit 1
-test -x "$D/travis-continuous.sh" || exit 1
-test -x "$D/travis-coverity.sh" || exit 1
+test -d "$D" || { echo "! No directory $D" ; exit 1 ; }
+test -x "$D/travis-continuous.sh" || { echo "! Missing -continuous" ; exit 1 ; }
+test -x "$D/travis-coverity.sh" || { echo "! Missing -coverity" ; exit 1 ; }
 
-test -f "$D/travis-common.sh" && . "$D/travis-config.sh"
+test -f "$D/travis-config.sh" && . "$D/travis-config.sh"
 
 if test "$TRAVIS_EVENT_TYPE" = "cron" ; then
   exec "$D/travis-coverity.sh"
diff --git a/src/modules/displaymanager/main.py b/src/modules/displaymanager/main.py
index f0b7ad787..6835a46a1 100644
--- a/src/modules/displaymanager/main.py
+++ b/src/modules/displaymanager/main.py
@@ -23,16 +23,43 @@
 #   You should have received a copy of the GNU General Public License
 #   along with Calamares. If not, see <http://www.gnu.org/licenses/>.
 
+import abc
 import os
-import collections
 import re
 import libcalamares
 import configparser
 
+from libcalamares.utils import gettext_path, gettext_languages
+
+import gettext
+_translation = gettext.translation("calamares-python",
+                                   localedir=gettext_path(),
+                                   languages=gettext_languages(),
+                                   fallback=True)
+_ = _translation.gettext
+_n = _translation.ngettext
+
+class DesktopEnvironment:
+    """
+    Desktop Environment -- some utility functions for a desktop
+    environment (e.g. finding out if it is installed). This
+    is independent of the *Display Manager*, which is what
+    we're configuring in this module.
+    """
+    def __init__(self, exec, desktop):
+        self.executable = exec
+        self.desktop_file = desktop
+
+    def find_desktop_environment(self, root_mount_point):
+        """
+        Check if this environment is installed in the
+        target system at @p root_mount_point.
+        """
+        return (
+            os.path.exists("{!s}{!s}".format(root_mount_point, self.executable)) and
+            os.path.exists("{!s}/usr/share/xsessions/{!s}.desktop".format(root_mount_point, self.desktop_file))
+            )
 
-DesktopEnvironment = collections.namedtuple(
-    'DesktopEnvironment', ['executable', 'desktop_file']
-    )
 
 desktop_environments = [
     DesktopEnvironment('/usr/bin/startkde', 'plasma'),  # KDE Plasma 5
@@ -67,54 +94,80 @@ def find_desktop_environment(root_mount_point):
     :return:
     """
     for desktop_environment in desktop_environments:
-        if (os.path.exists("{!s}{!s}".format(
-                    root_mount_point, desktop_environment.executable
-                    )
-                ) and os.path.exists(
-                    "{!s}/usr/share/xsessions/{!s}.desktop".format(
-                        root_mount_point, desktop_environment.desktop_file
-                    )
-                )):
+        if desktop_environment.find_desktop_environment(root_mount_point):
             return desktop_environment
     return None
 
 
-def have_dm(dm_name, root_mount_point):
+class DisplayManager(metaclass=abc.ABCMeta):
     """
-    Checks if display manager is properly installed.
+    Display Manager -- a base class for DM configuration.
+    """
+    name = None
+    executable = None
 
-    :param dm_name:
-    :param root_mount_point:
-    :return:
-    """
-    bin_path = "{!s}/usr/bin/{!s}".format(root_mount_point, dm_name)
-    sbin_path = "{!s}/usr/sbin/{!s}".format(root_mount_point, dm_name)
-    return (os.path.exists(bin_path)
+    def __init__(self, root_mount_point):
+        self.root_mount_point = root_mount_point
+
+    def have_dm(self):
+        """
+        Is this DM installed in the target system?
+        The default implementation checks for `executable`
+        in the target system.
+        """
+        if self.executable is None:
+            return True
+
+        bin_path = "{!s}/usr/bin/{!s}".format(self.root_mount_point, self.executable)
+        sbin_path = "{!s}/usr/sbin/{!s}".format(self.root_mount_point, self.executable)
+        return (
+            os.path.exists(bin_path)
             or os.path.exists(sbin_path)
             )
 
+    # The four abstract methods below are called in the order listed here.
+    # They must all be implemented by subclasses, but not all of them
+    # actually do something for all DMs.
 
-def set_autologin(username,
-                  displaymanager,
-                  default_desktop_environment,
-                  root_mount_point):
-    """
-    Enables automatic login for the installed desktop managers.
+    @abc.abstractmethod
+    def basic_setup(self):
+        """
+        Do basic setup (e.g. users, groups, directory creation) for this DM.
+        """
+        # Some implementations do nothing
 
-    :param username:
-    :param displaymanager: str
-        The displaymanager for which to configure autologin.
-    :param default_desktop_environment:
-    :param root_mount_point:
-    """
-    do_autologin = True
+    @abc.abstractmethod
+    def desktop_environment_setup(self, desktop_environment):
+        """
+        Configure the given @p desktop_environment as the default one, in
+        the configuration files for this DM.
+        """
+        # Many implementations do nothing
 
-    if username is None:
-        do_autologin = False
+    @abc.abstractmethod
+    def greeter_setup(self):
+        """
+        Additional setup for the greeter.
+        """
+        # Most implementations do nothing
 
-    if "mdm" == displaymanager:
+    @abc.abstractmethod
+    def set_autologin(self, username, do_autologin, default_desktop_environment):
+        """
+        Configure the DM inside the given @p root_mount_point with
+        autologin (if @p do_autologin is True) for the given @p username.
+        If the DM supports it, set the default DE to @p default_desktop_environment
+        as well.
+        """
+
+
+class DMmdm(DisplayManager):
+    name = "mdm"
+    executable = "mdm"
+
+    def set_autologin(self, username, do_autologin, default_desktop_environment):
         # Systems with MDM as Desktop Manager
-        mdm_conf_path = os.path.join(root_mount_point, "etc/mdm/custom.conf")
+        mdm_conf_path = os.path.join(self.root_mount_point, "etc/mdm/custom.conf")
 
         if os.path.exists(mdm_conf_path):
             with open(mdm_conf_path, 'r') as mdm_conf:
@@ -149,9 +202,58 @@ def set_autologin(username,
                 else:
                     mdm_conf.write('AutomaticLoginEnable=False\n')
 
-    if "gdm" == displaymanager:
+    def basic_setup(self):
+        if libcalamares.utils.target_env_call(
+                    ['getent', 'group', 'mdm']
+                    ) != 0:
+            libcalamares.utils.target_env_call(
+                ['groupadd', '-g', '128', 'mdm']
+                )
+
+        if libcalamares.utils.target_env_call(
+                ['getent', 'passwd', 'mdm']
+                ) != 0:
+            libcalamares.utils.target_env_call(
+                ['useradd',
+                    '-c', '"Linux Mint Display Manager"',
+                    '-u', '128',
+                    '-g', 'mdm',
+                    '-d', '/var/lib/mdm',
+                    '-s', '/usr/bin/nologin',
+                    'mdm'
+                    ]
+                )
+
+        libcalamares.utils.target_env_call(
+            ['passwd', '-l', 'mdm']
+            )
+        libcalamares.utils.target_env_call(
+            ['chown', 'root:mdm', '/var/lib/mdm']
+            )
+        libcalamares.utils.target_env_call(
+            ['chmod', '1770', '/var/lib/mdm']
+            )
+
+    def desktop_environment_setup(self, default_desktop_environment):
+        os.system(
+            "sed -i \"s|default.desktop|{!s}.desktop|g\" "
+            "{!s}/etc/mdm/custom.conf".format(
+                default_desktop_environment.desktop_file,
+                self.root_mount_point
+                )
+            )
+
+    def greeter_setup(self):
+        pass
+
+
+class DMgdm(DisplayManager):
+    name = "gdm"
+    executable = "gdm"
+
+    def set_autologin(self, username, do_autologin, default_desktop_environment):
         # Systems with GDM as Desktop Manager
-        gdm_conf_path = os.path.join(root_mount_point, "etc/gdm/custom.conf")
+        gdm_conf_path = os.path.join(self.root_mount_point, "etc/gdm/custom.conf")
 
         if os.path.exists(gdm_conf_path):
             with open(gdm_conf_path, 'r') as gdm_conf:
@@ -185,7 +287,7 @@ def set_autologin(username,
 
         if (do_autologin):
             accountservice_dir = "{!s}/var/lib/AccountsService/users".format(
-                    root_mount_point
+                    self.root_mount_point
                     )
             userfile_path = "{!s}/{!s}".format(accountservice_dir, username)
             if os.path.exists(accountservice_dir):
@@ -198,10 +300,51 @@ def set_autologin(username,
 
                     userfile.write("Icon=\n")
 
-    if "kdm" == displaymanager:
+
+    def basic_setup(self):
+        if libcalamares.utils.target_env_call(
+                ['getent', 'group', 'gdm']
+                ) != 0:
+            libcalamares.utils.target_env_call(
+                ['groupadd', '-g', '120', 'gdm']
+                )
+
+        if libcalamares.utils.target_env_call(
+                ['getent', 'passwd', 'gdm']
+                ) != 0:
+            libcalamares.utils.target_env_call(
+                ['useradd',
+                    '-c', '"Gnome Display Manager"',
+                    '-u', '120',
+                    '-g', 'gdm',
+                    '-d', '/var/lib/gdm',
+                    '-s', '/usr/bin/nologin',
+                    'gdm'
+                    ]
+                )
+
+        libcalamares.utils.target_env_call(
+            ['passwd', '-l', 'gdm']
+            )
+        libcalamares.utils.target_env_call(
+            ['chown', '-R', 'gdm:gdm', '/var/lib/gdm']
+            )
+
+    def desktop_environment_setup(self, desktop_environment):
+        pass
+
+    def greeter_setup(self):
+        pass
+
+
+class DMkdm(DisplayManager):
+    name = "kdm"
+    executable = "kdm"
+
+    def set_autologin(self, username, do_autologin, default_desktop_environment):
         # Systems with KDM as Desktop Manager
         kdm_conf_path = os.path.join(
-            root_mount_point, "usr/share/config/kdm/kdmrc"
+            self.root_mount_point, "usr/share/config/kdm/kdmrc"
             )
         # Check which path is in use: SUSE does something else.
         # Also double-check the default setting. Pick the first
@@ -210,7 +353,7 @@ def set_autologin(username,
             "usr/share/config/kdm/kdmrc",
             "usr/share/kde4/config/kdm/kdmrc",
         ):
-            p = os.path.join(root_mount_point, candidate_kdmrc)
+            p = os.path.join(self.root_mount_point, candidate_kdmrc)
             if os.path.exists(p):
                 kdm_conf_path = p
                 break
@@ -234,13 +377,51 @@ def set_autologin(username,
                     kdm_conf.write(line)
         else:
             return (
-                "Cannot write KDM configuration file",
-                "KDM config file {!s} does not exist".format(kdm_conf_path)
+                _("Cannot write KDM configuration file"),
+                _("KDM config file {!s} does not exist").format(kdm_conf_path)
                 )
 
-    if "lxdm" == displaymanager:
+    def basic_setup(self):
+        if libcalamares.utils.target_env_call(
+                ['getent', 'group', 'kdm']
+                ) != 0:
+            libcalamares.utils.target_env_call(
+                ['groupadd', '-g', '135', 'kdm']
+                )
+
+        if libcalamares.utils.target_env_call(
+                ['getent', 'passwd', 'kdm']
+                ) != 0:
+            libcalamares.utils.target_env_call(
+                ['useradd',
+                    '-u', '135',
+                    '-g', 'kdm',
+                    '-d', '/var/lib/kdm',
+                    '-s', '/bin/false',
+                    '-r',
+                    '-M',
+                    'kdm'
+                    ]
+                )
+
+        libcalamares.utils.target_env_call(
+            ['chown', '-R', '135:135', 'var/lib/kdm']
+            )
+
+    def desktop_environment_setup(self, desktop_environment):
+        pass
+
+    def greeter_setup(self):
+        pass
+
+
+class DMlxdm(DisplayManager):
+    name = "lxdm"
+    executable = "lxdm"
+
+    def set_autologin(self, username, do_autologin, default_desktop_environment):
         # Systems with LXDM as Desktop Manager
-        lxdm_conf_path = os.path.join(root_mount_point, "etc/lxdm/lxdm.conf")
+        lxdm_conf_path = os.path.join(self.root_mount_point, "etc/lxdm/lxdm.conf")
         text = []
 
         if os.path.exists(lxdm_conf_path):
@@ -258,17 +439,52 @@ def set_autologin(username,
                     lxdm_conf.write(line)
         else:
             return (
-                "Cannot write LXDM configuration file",
-                "LXDM config file {!s} does not exist".format(lxdm_conf_path)
+                _("Cannot write LXDM configuration file"),
+                _("LXDM config file {!s} does not exist").format(lxdm_conf_path)
                 )
 
-    if "lightdm" == displaymanager:
+    def basic_setup(self):
+        if libcalamares.utils.target_env_call(
+                ['getent', 'group', 'lxdm']
+                ) != 0:
+            libcalamares.utils.target_env_call(
+                ['groupadd', '--system', 'lxdm']
+                )
+
+        libcalamares.utils.target_env_call(
+            ['chgrp', '-R', 'lxdm', '/var/lib/lxdm']
+            )
+        libcalamares.utils.target_env_call(
+            ['chgrp', 'lxdm', '/etc/lxdm/lxdm.conf']
+            )
+        libcalamares.utils.target_env_call(
+            ['chmod', '+r', '/etc/lxdm/lxdm.conf']
+            )
+
+    def desktop_environment_setup(self, default_desktop_environment):
+        os.system(
+            "sed -i -e \"s|^.*session=.*|session={!s}|\" "
+            "{!s}/etc/lxdm/lxdm.conf".format(
+                default_desktop_environment.executable,
+                self.root_mount_point
+                )
+            )
+
+    def greeter_setup(self):
+        pass
+
+
+class DMlightdm(DisplayManager):
+    name = "lightdm"
+    executable = "lightdm"
+
+    def set_autologin(self, username, do_autologin, default_desktop_environment):
         # Systems with LightDM as Desktop Manager
         # Ideally, we should use configparser for the ini conf file,
         # but we just do a simple text replacement for now, as it
         # worksforme(tm)
         lightdm_conf_path = os.path.join(
-            root_mount_point, "etc/lightdm/lightdm.conf"
+            self.root_mount_point, "etc/lightdm/lightdm.conf"
             )
         text = []
 
@@ -298,15 +514,93 @@ def set_autologin(username,
                             "#autologin-user=\n")
             except FileNotFoundError:
                 return (
-                    "Cannot write LightDM configuration file",
-                    "LightDM config file {!s} does not exist".format(
-                        lightdm_conf_path
-                        )
+                    _("Cannot write LightDM configuration file"),
+                    _("LightDM config file {!s} does not exist").format(lightdm_conf_path)
                     )
 
-    if "slim" == displaymanager:
+
+    def basic_setup(self):
+        libcalamares.utils.target_env_call(
+            ['mkdir', '-p', '/run/lightdm']
+            )
+
+        if libcalamares.utils.target_env_call(
+                ['getent', 'group', 'lightdm']
+                ) != 0:
+            libcalamares.utils.target_env_call(
+                ['groupadd', '-g', '620', 'lightdm']
+                )
+
+        if libcalamares.utils.target_env_call(
+                ['getent', 'passwd', 'lightdm']
+                ) != 0:
+            libcalamares.utils.target_env_call(
+                ['useradd', '-c',
+                    '"LightDM Display Manager"',
+                    '-u', '620',
+                    '-g', 'lightdm',
+                    '-d', '/var/run/lightdm',
+                    '-s', '/usr/bin/nologin',
+                    'lightdm'
+                    ]
+                )
+
+        libcalamares.utils.target_env_call(['passwd', '-l', 'lightdm'])
+        libcalamares.utils.target_env_call(['chown', '-R', 'lightdm:lightdm', '/run/lightdm'])
+        libcalamares.utils.target_env_call(['chmod', '+r' '/etc/lightdm/lightdm.conf'])
+
+    def desktop_environment_setup(self, default_desktop_environment):
+        os.system(
+            "sed -i -e \"s/^.*user-session=.*/user-session={!s}/\" "
+            "{!s}".format(
+                default_desktop_environment.desktop_file,
+                lightdm_conf_path
+                )
+            )
+
+    def greeter_setup(self):
+        lightdm_conf_path = os.path.join(
+            self.root_mount_point, "etc/lightdm/lightdm.conf"
+            )
+
+        # configure lightdm-greeter
+        greeter_path = os.path.join(
+            self.root_mount_point, "usr/share/xgreeters"
+            )
+
+        if (os.path.exists(greeter_path)):
+            # configure first found lightdm-greeter
+            for entry in os.listdir(greeter_path):
+                if entry.endswith('.desktop'):
+                    greeter = entry.split('.')[0]
+                    libcalamares.utils.debug(
+                        "found greeter {!s}".format(greeter)
+                        )
+                    os.system(
+                        "sed -i -e \"s/^.*greeter-session=.*"
+                        "/greeter-session={!s}/\" {!s}".format(
+                            greeter,
+                            lightdm_conf_path
+                            )
+                        )
+                    libcalamares.utils.debug(
+                        "{!s} configured as greeter.".format(greeter)
+                        )
+                    break
+            else:
+                return (
+                    _("Cannot configure LightDM"),
+                    _("No LightDM greeter installed.")
+                    )
+
+
+class DMslim(DisplayManager):
+    name = "slim"
+    executable = "slim"
+
+    def set_autologin(self, username, do_autologin, default_desktop_environment):
         # Systems with Slim as Desktop Manager
-        slim_conf_path = os.path.join(root_mount_point, "etc/slim.conf")
+        slim_conf_path = os.path.join(self.root_mount_point, "etc/slim.conf")
         text = []
 
         if os.path.exists(slim_conf_path):
@@ -327,13 +621,28 @@ def set_autologin(username,
                     slim_conf.write(line)
         else:
             return (
-                "Cannot write SLIM configuration file",
-                "SLIM config file {!s} does not exist".format(slim_conf_path)
+                _("Cannot write SLIM configuration file"),
+                _("SLIM config file {!s} does not exist").format(slim_conf_path)
                 )
 
-    if "sddm" == displaymanager:
+
+    def basic_setup(self):
+        pass
+
+    def desktop_environment_setup(self, desktop_environment):
+        pass
+
+    def greeter_setup(self):
+        pass
+
+
+class DMsddm(DisplayManager):
+    name = "sddm"
+    executable = "sddm"
+
+    def set_autologin(self, username, do_autologin, default_desktop_environment):
         # Systems with Sddm as Desktop Manager
-        sddm_conf_path = os.path.join(root_mount_point, "etc/sddm.conf")
+        sddm_conf_path = os.path.join(self.root_mount_point, "etc/sddm.conf")
 
         sddm_config = configparser.ConfigParser(strict=False)
         # Make everything case sensitive
@@ -360,7 +669,22 @@ def set_autologin(username,
         with open(sddm_conf_path, 'w') as sddm_config_file:
             sddm_config.write(sddm_config_file, space_around_delimiters=False)
 
-    if "sysconfig" == displaymanager:
+
+    def basic_setup(self):
+        pass
+
+    def desktop_environment_setup(self, desktop_environment):
+        pass
+
+    def greeter_setup(self):
+        pass
+
+
+class DMsysconfig(DisplayManager):
+    name = "sysconfig"
+    executable = None
+
+    def set_autologin(self, username, do_autologin, default_desktop_environment):
         dmauto = "DISPLAYMANAGER_AUTOLOGIN"
 
         os.system(
@@ -368,11 +692,28 @@ def set_autologin(username,
             "{!s}/etc/sysconfig/displaymanager".format(
                             dmauto, dmauto,
                             username if do_autologin else "",
-                            root_mount_point
+                            self.root_mount_point
                             )
             )
 
-    return None
+
+    def basic_setup(self):
+        pass
+
+    def desktop_environment_setup(self, desktop_environment):
+        pass
+
+    def greeter_setup(self):
+        pass
+
+
+# Collect all the subclasses of DisplayManager defined above,
+# and index them based on the name property of each class.
+display_managers = [
+    (c.name, c)
+    for c in globals().values()
+    if type(c) is abc.ABCMeta and issubclass(c, DisplayManager) and c.name
+]
 
 
 def run():
@@ -386,6 +727,7 @@ def run():
     If a displaymanager is in the list but not installed, a debugging message
     is printed and the entry ignored.
     """
+    # Get configuration settings for display managers
     displaymanagers = None
     if "displaymanagers" in libcalamares.job.configuration:
         displaymanagers = libcalamares.job.configuration["displaymanagers"]
@@ -393,16 +735,46 @@ def run():
     if libcalamares.globalstorage.contains("displayManagers"):
         displaymanagers = libcalamares.globalstorage.value("displayManagers")
 
-    if displaymanagers is None:
+    if not displaymanagers:
         return (
-            "No display managers selected for the displaymanager module.",
-            "The displaymanagers list is empty or undefined in both"
-            "globalstorage and displaymanager.conf."
+            _("No display managers selected for the displaymanager module."),
+            _("The displaymanagers list is empty or undefined in both"
+            "globalstorage and displaymanager.conf.")
             )
 
-    username = libcalamares.globalstorage.value("autologinUser")
+    # Get instances that are actually installed
     root_mount_point = libcalamares.globalstorage.value("rootMountPoint")
+    dm_impl = []
+    dm_names = displaymanagers[:]
+    if ("sysconfigSetup" in libcalamares.job.configuration
+            and libcalamares.job.configuration["sysconfigSetup"]):
+        dm_names.append("sysconfig")
+    for dm in dm_names:
+        # Find the implementation class
+        dm_instance = None
+        impl = [ cls for name, cls in display_managers if name == dm ]
+        if len(impl) == 1:
+            dm_instance = impl[0](root_mount_point)
+            if dm_instance.have_dm():
+                dm_impl.append(dm_instance)
+            else:
+                dm_instance = None
+        else:
+            libcalamares.utils.debug("{!s} has {!d} implementation classes.".format(dm).format(len(impl)))
 
+        if dm_instance is None:
+            libcalamares.utils.debug("{!s} selected but not installed".format(dm))
+            if dm in displaymanagers:
+                displaymanagers.remove(dm)
+
+    if not dm_impl:
+        return (
+            _("No display managers selected for the displaymanager module."),
+            _("The list is empty after checking for installed display managers.")
+            )
+
+
+    # Pick up remaining settings
     if "defaultDesktopEnvironment" in libcalamares.job.configuration:
         entry = libcalamares.job.configuration["defaultDesktopEnvironment"]
         default_desktop_environment = DesktopEnvironment(
@@ -418,269 +790,34 @@ def run():
     else:
         enable_basic_setup = False
 
-    # Setup slim
-    if "slim" in displaymanagers:
-        if not have_dm("slim", root_mount_point):
-            libcalamares.utils.debug("slim selected but not installed")
-            displaymanagers.remove("slim")
-
-    # Setup sddm
-    if "sddm" in displaymanagers:
-        if not have_dm("sddm", root_mount_point):
-            libcalamares.utils.debug("sddm selected but not installed")
-            displaymanagers.remove("sddm")
-
-    # setup lightdm
-    if "lightdm" in displaymanagers:
-        if have_dm("lightdm", root_mount_point):
-            lightdm_conf_path = os.path.join(
-                root_mount_point, "etc/lightdm/lightdm.conf"
-                )
-
-            if enable_basic_setup:
-                libcalamares.utils.target_env_call(
-                    ['mkdir', '-p', '/run/lightdm']
-                    )
-
-                if libcalamares.utils.target_env_call(
-                        ['getent', 'group', 'lightdm']
-                        ) != 0:
-                    libcalamares.utils.target_env_call(
-                        ['groupadd', '-g', '620', 'lightdm']
-                        )
-
-                if libcalamares.utils.target_env_call(
-                        ['getent', 'passwd', 'lightdm']
-                        ) != 0:
-                    libcalamares.utils.target_env_call(
-                        ['useradd', '-c',
-                            '"LightDM Display Manager"',
-                            '-u', '620',
-                            '-g', 'lightdm',
-                            '-d', '/var/run/lightdm',
-                            '-s', '/usr/bin/nologin',
-                            'lightdm'
-                         ]
-                        )
-
-                libcalamares.utils.target_env_call('passwd', '-l', 'lightdm')
-                libcalamares.utils.target_env_call(
-                    ['chown', '-R', 'lightdm:lightdm', '/run/lightdm']
-                    )
-                libcalamares.utils.target_env_call(
-                    ['chmod', '+r' '/etc/lightdm/lightdm.conf']
-                    )
-
-            if default_desktop_environment is not None:
-                os.system(
-                    "sed -i -e \"s/^.*user-session=.*/user-session={!s}/\" "
-                    "{!s}".format(
-                        default_desktop_environment.desktop_file,
-                        lightdm_conf_path
-                        )
-                    )
-
-            # configure lightdm-greeter
-            greeter_path = os.path.join(
-                root_mount_point, "usr/share/xgreeters"
-                )
-
-            if (os.path.exists(greeter_path)):
-                # configure first found lightdm-greeter
-                for entry in os.listdir(greeter_path):
-                    if entry.endswith('.desktop'):
-                        greeter = entry.split('.')[0]
-                        libcalamares.utils.debug(
-                            "found greeter {!s}".format(greeter)
-                            )
-                        os.system(
-                            "sed -i -e \"s/^.*greeter-session=.*"
-                            "/greeter-session={!s}/\" {!s}".format(
-                                greeter,
-                                lightdm_conf_path
-                                )
-                            )
-                        libcalamares.utils.debug(
-                            "{!s} configured as greeter.".format(greeter)
-                            )
-                        break
-                else:
-                    return ("No lightdm greeter installed.")
-        else:
-            libcalamares.utils.debug("lightdm selected but not installed")
-            displaymanagers.remove("lightdm")
-
-    # Setup gdm
-    if "gdm" in displaymanagers:
-        if have_dm("gdm", root_mount_point):
-            if enable_basic_setup:
-                if libcalamares.utils.target_env_call(
-                        ['getent', 'group', 'gdm']
-                        ) != 0:
-                    libcalamares.utils.target_env_call(
-                        ['groupadd', '-g', '120', 'gdm']
-                        )
-
-                if libcalamares.utils.target_env_call(
-                        ['getent', 'passwd', 'gdm']
-                        ) != 0:
-                    libcalamares.utils.target_env_call(
-                        ['useradd',
-                            '-c', '"Gnome Display Manager"',
-                            '-u', '120',
-                            '-g', 'gdm',
-                            '-d', '/var/lib/gdm',
-                            '-s', '/usr/bin/nologin',
-                            'gdm'
-                         ]
-                        )
-
-                libcalamares.utils.target_env_call(
-                    ['passwd', '-l', 'gdm']
-                    )
-                libcalamares.utils.target_env_call(
-                    ['chown', '-R', 'gdm:gdm', '/var/lib/gdm']
-                    )
-        else:
-            libcalamares.utils.debug("gdm selected but not installed")
-            displaymanagers.remove("gdm")
-
-    # Setup mdm
-    if "mdm" in displaymanagers:
-        if have_dm("mdm", root_mount_point):
-            if enable_basic_setup:
-                if libcalamares.utils.target_env_call(
-                         ['getent', 'group', 'mdm']
-                         ) != 0:
-                    libcalamares.utils.target_env_call(
-                        ['groupadd', '-g', '128', 'mdm']
-                        )
-
-                if libcalamares.utils.target_env_call(
-                        ['getent', 'passwd', 'mdm']
-                        ) != 0:
-                    libcalamares.utils.target_env_call(
-                        ['useradd',
-                            '-c', '"Linux Mint Display Manager"',
-                            '-u', '128',
-                            '-g', 'mdm',
-                            '-d', '/var/lib/mdm',
-                            '-s', '/usr/bin/nologin',
-                            'mdm'
-                         ]
-                        )
-
-                libcalamares.utils.target_env_call(
-                    ['passwd', '-l', 'mdm']
-                    )
-                libcalamares.utils.target_env_call(
-                    ['chown', 'root:mdm', '/var/lib/mdm']
-                    )
-                libcalamares.utils.target_env_call(
-                    ['chmod', '1770', '/var/lib/mdm']
-                    )
-
-            if default_desktop_environment is not None:
-                os.system(
-                    "sed -i \"s|default.desktop|{!s}.desktop|g\" "
-                    "{!s}/etc/mdm/custom.conf".format(
-                        default_desktop_environment.desktop_file,
-                        root_mount_point
-                        )
-                    )
-        else:
-            libcalamares.utils.debug("mdm selected but not installed")
-            displaymanagers.remove("mdm")
-
-    # Setup lxdm
-    if "lxdm" in displaymanagers:
-        if have_dm("lxdm", root_mount_point):
-            if enable_basic_setup:
-                if libcalamares.utils.target_env_call(
-                        ['getent', 'group', 'lxdm']
-                        ) != 0:
-                    libcalamares.utils.target_env_call(
-                        ['groupadd', '--system', 'lxdm']
-                        )
-
-                libcalamares.utils.target_env_call(
-                    ['chgrp', '-R', 'lxdm', '/var/lib/lxdm']
-                    )
-                libcalamares.utils.target_env_call(
-                    ['chgrp', 'lxdm', '/etc/lxdm/lxdm.conf']
-                    )
-                libcalamares.utils.target_env_call(
-                    ['chmod', '+r', '/etc/lxdm/lxdm.conf']
-                    )
-
-            if default_desktop_environment is not None:
-                os.system(
-                    "sed -i -e \"s|^.*session=.*|session={!s}|\" "
-                    "{!s}/etc/lxdm/lxdm.conf".format(
-                        default_desktop_environment.executable,
-                        root_mount_point
-                        )
-                    )
-        else:
-            libcalamares.utils.debug("lxdm selected but not installed")
-            displaymanagers.remove("lxdm")
-
-    # Setup kdm
-    if "kdm" in displaymanagers:
-        if have_dm("kdm", root_mount_point):
-            if enable_basic_setup:
-                if libcalamares.utils.target_env_call(
-                        ['getent', 'group', 'kdm']
-                        ) != 0:
-                    libcalamares.utils.target_env_call(
-                        ['groupadd', '-g', '135', 'kdm']
-                        )
-
-                if libcalamares.utils.target_env_call(
-                        ['getent', 'passwd', 'kdm']
-                        ) != 0:
-                    libcalamares.utils.target_env_call(
-                        ['useradd',
-                            '-u', '135',
-                            '-g', 'kdm',
-                            '-d', '/var/lib/kdm',
-                            '-s', '/bin/false',
-                            '-r',
-                            '-M',
-                            'kdm'
-                         ]
-                        )
-
-                libcalamares.utils.target_env_call(
-                    ['chown', '-R', '135:135', 'var/lib/kdm']
-                    )
-        else:
-            libcalamares.utils.debug("kdm selected but not installed")
-            displaymanagers.remove("kdm")
-
+    username = libcalamares.globalstorage.value("autologinUser")
     if username is not None:
-        libcalamares.utils.debug(
-            "Setting up autologin for user {!s}.".format(username)
-            )
+        do_autologin = True
+        libcalamares.utils.debug("Setting up autologin for user {!s}.".format(username))
     else:
+        do_autologin = False
         libcalamares.utils.debug("Unsetting autologin.")
 
     libcalamares.globalstorage.insert("displayManagers", displaymanagers)
 
+    # Do the actual configuration and collect messages
     dm_setup_message = []
-    for dm in displaymanagers:
-        dm_message = set_autologin(
-                        username, dm,
-                        default_desktop_environment,
-                        root_mount_point
-                        )
+    for dm in dm_impl:
+        dm_message = None
+        if enable_basic_setup:
+            dm_message = dm.basic_setup()
+        if default_desktop_environment is not None and dm_message is None:
+            dm_message = dm.desktop_environment_setup(default_desktop_environment)
+        if dm_message is None:
+            dm_message = dm.greeter_setup()
+        if dm_message is None:
+            dm_message = dm.set_autologin(username, do_autologin, default_desktop_environment)
+
         if dm_message is not None:
             dm_setup_message.append("{!s}: {!s}".format(*dm_message))
 
-    if ("sysconfigSetup" in libcalamares.job.configuration
-            and libcalamares.job.configuration["sysconfigSetup"]):
-        set_autologin(username, "sysconfig", None, root_mount_point)
-
     if dm_setup_message:
-        return ("Display manager configuration was incomplete",
-                "\n".join(dm_setup_message))
+        return (
+            _("Display manager configuration was incomplete"),
+            "\n".join(dm_setup_message)
+            )