Index: gnome-orca-2.91.92/src/orca/orca.py
===================================================================
--- gnome-orca-2.91.92.orig/src/orca/orca.py	2011-03-22 07:27:01.000000000 +1100
+++ gnome-orca-2.91.92/src/orca/orca.py	2011-03-22 13:49:41.871928707 +1100
@@ -2290,6 +2290,20 @@
     except:
         debug.printException(debug.LEVEL_SEVERE)
 
+    environ_message = None
+    if os.getenv("ORCA_DESKTOP_ENV") == "unity":
+        environ_message = _("Current desktop environment is unity.")
+    elif os.getenv("ORCA_DESKTOP_ENV") == "gnome":
+        environ_message = _("Current desktop environment is classic GNOME.")
+
+    if environ_message:
+        try:
+            if not _settingsManager.getSetting('onlySpeakDisplayedText'):
+                speech.speak(environ_message, settings.voices.get(settings.SYSTEM_VOICE))
+            braille.displayMessage(environ_message)
+        except:
+            debug.printException(debug.LEVEL_SEVERE)
+
     # Check to see if the user wants the configuration GUI. It's
     # done here so that the user's existing preferences can be used
     # to set the initial GUI state.  We'll also force the set to
Index: gnome-orca-2.91.92/src/orca/common_keyboardmap.py
===================================================================
--- gnome-orca-2.91.92.orig/src/orca/common_keyboardmap.py	2011-03-08 23:51:51.000000000 +1100
+++ gnome-orca-2.91.92/src/orca/common_keyboardmap.py	2011-03-22 13:49:41.871928707 +1100
@@ -82,6 +82,8 @@
     ("Home", defaultModifierMask, ORCA_CTRL_ALT_MODIFIER_MASK,
     "reportScriptInfoHandler"),
 
+    ("e", defaultModifierMask, ORCA_MODIFIER_MASK,
+    "presentDesktopEnvironmentHandler"),
 
     ("Page_Up", defaultModifierMask, ORCA_CTRL_ALT_MODIFIER_MASK,
     "printAncestryHandler"),
Index: gnome-orca-2.91.92/src/orca/scripts/default.py
===================================================================
--- gnome-orca-2.91.92.orig/src/orca/scripts/default.py	2011-03-08 23:51:51.000000000 +1100
+++ gnome-orca-2.91.92/src/orca/scripts/default.py	2011-03-22 13:50:10.611928696 +1100
@@ -32,6 +32,7 @@
 
 import locale
 import time
+import os
 
 import orca.orca as orca
 _settingsManager = getattr(orca, '_settingsManager')
@@ -1097,6 +1098,15 @@
                 #
                 _("Passes the next command on to the current application."))
 
+        self.inputEventHandlers["presentDesktopEnvironmentHandler"] = \
+            input_event.InputEventHandler(
+                Script.presentDesktopEnvironment,
+                # Translators: Orca can present the current desktop
+                # environment to the user when the user presses a
+                # shortcut key.
+                #
+                _("Present current desktop environment."))
+
         self.inputEventHandlers.update(notification_messages.inputEventHandlers)
 
     def getInputEventHandlerKey(self, inputEventHandler):
@@ -5824,6 +5834,22 @@
         self.presentMessage(message)
         return True
 
+    def presentDesktopEnvironment(self, inputEvent):
+        """ Tells the user what desktop environment they are running. """
+        environment = None
+        if os.getenv("ORCA_DESKTOP_ENV") == "unity":
+            environment = _("unity")
+        elif os.getenv("ORCA_DESKTOP_ENV") == "gnome":
+            environment = _("classic GNOME")
+        if environment:
+            verbosity = _settingsManager.getSetting('speechVerbosityLevel')
+            if verbosity == settings.VERBOSITY_LEVEL_VERBOSE:
+                self.presentMessage(_("Current desktop environment is %s") % environment)
+            else:
+                self.presentMessage(environment)
+        return True
+
+
 # Dictionary that defines the state changes we care about for various
 # objects.  The key represents the role and the value represents a list
 # of states that we care about.
Index: gnome-orca-2.91.92/src/orca/orca.in
===================================================================
--- gnome-orca-2.91.92.orig/src/orca/orca.in	2011-03-22 13:49:41.861928707 +1100
+++ gnome-orca-2.91.92/src/orca/orca.in	2011-03-22 13:50:10.611928696 +1100
@@ -109,6 +109,20 @@
     done
 }
 
+checkDesktopEnv()
+{
+    if [ "$DESKTOP_SESSION" = "gnome" ]; then
+        if xprop -root | grep -q COMPIZ ; then
+            export ORCA_DESKTOP_ENV="unity"
+        else
+            export ORCA_DESKTOP_ENV="gnome"
+        fi
+    elif [ -n "$DESKTOP_SESSION" ] && \
+         echo $DESKTOP_SESSION | grep -q ^gnome- ; then
+        export ORCA_DESKTOP_ENV="gnome"
+    fi
+}
+
 trap cleanup HUP QUIT TERM INT ABRT
 
 # Runs orca.
@@ -119,6 +133,7 @@
     PYTHONPATH=${PYTHONPATH}:@pyexecdir@
     export PYTHONPATH
     saveXmodmap
+    checkDesktopEnv
     @PYTHON@ -c "import orca.orca; orca.orca.main()" "$ARGS"
     restoreXmodmap
 }