diff --git a/lib/configure.py b/lib/configure.py
index 62f32751e6..e08032af81 100644
--- a/lib/configure.py
+++ b/lib/configure.py
@@ -730,35 +730,73 @@ def checkModulesConfig():
   tx.close()
   print '\tdone'
 
+
 def processModuleFile(file, bool_docbook, bool_linuxdoc):
     ''' process module file and get a line of result
 
-        Declare lines look like this:
-          \DeclareLyXModule[LaTeX Packages]{Description}{ModuleName}...
+        The top of a module file should look like this:
+          #\DeclareLyXModule[LaTeX Packages]{ModuleName}
+          #BeginDescription
+          #...body of description...
+          #EndDescription
+          #Requires: [list of required modules]
+          #Excludes: [list of excluded modules]
+        The last two lines are optional
         We expect output:
-          "ModuleName" "filename" "Description" "Packages"
-        "
+          "ModuleName" "filename" "Description" "Packages" "Requires" "Excludes"
     '''
-    p = re.compile(r'\DeclareLyXModule\s*(?:\[([^]]*)\])?{(.*)}{(.*)}')
-    for line in open(file).readlines():
-        res = p.search(line)
-        if res != None:
-            (packages, desc, modname) = res.groups()
-            #check availability...need to add that
-            if packages == None:
-              packages = ""
-            else:
-              pkgs = [s.strip() for s in packages.split(",")]
-              packages = ",".join(pkgs)
+    p = re.compile(r'\DeclareLyXModule\s*(?:\[([^]]*?)\])?{(.*)}')
+    r = re.compile(r'#+\s*Requires: (.*)')
+    x = re.compile(r'#+\s*Excludes: (.*)')
+    b = re.compile(r'#+\s*DescriptionBegin\s*$')
+    e = re.compile(r'#+\s*DescriptionEnd\s*$')
 
-            filename = file.split(os.sep)[-1]
-            return '"%s" "%s" "%s" "%s"\n' % (modname, filename, desc, packages)
+    modname = desc = pkgs = req = excl = ""
+    readingDescription = False
+    descLines = []
+
+    for line in open(file).readlines():
+      if readingDescription:
+        res = e.search(line)
+        if res != None:
+          readingDescription = False
+          desc = " ".join(descLines)
+          continue
+        descLines.append(line[1:].strip())
+        continue
+      res = b.search(line)
+      if res != None:
+        readingDescription = True
+        continue
+      res = p.search(line)
+      if res != None:
+          (pkgs, modname) = res.groups()
+          if pkgs == None:
+            pkgs = ""
+          else:
+            tmp = [s.strip() for s in pkgs.split(",")]
+            pkgs = ",".join(tmp)
+
+          filename = file.split(os.sep)[-1]
+          continue
+      res = r.search(line)
+      if res != None:
+        req = res.group(1)
+        tmp = [s.strip() for s in req.split("|")]
+        req = "|".join(tmp)
+        continue
+      res = x.search(line)
+      if res != None:
+        excl = res.group(1)
+        tmp = [s.strip() for s in excl.split("|")]
+        excl = "|".join(tmp)
+        continue
+    if modname != "":
+        return '"%s" "%s" "%s" "%s" "%s" "%s"\n' % (modname, filename, desc, pkgs, req, excl)
     print "Module file without \DeclareLyXModule line. "
     sys.exit(2)
 
 
-
-
 def checkTeXAllowSpaces():
     ''' Let's check whether spaces are allowed in TeX file names '''
     tex_allows_spaces = 'false'
diff --git a/lib/doc/Customization.lyx b/lib/doc/Customization.lyx
index ef21ba39f7..cfa77fd0db 100644
--- a/lib/doc/Customization.lyx
+++ b/lib/doc/Customization.lyx
@@ -5862,22 +5862,82 @@ A module must begin with a line like the following:
 \begin_layout LyX-Code
 #
 \backslash
-DeclareLyXModule[endnotes.sty]{Adds an endnote inset.}{Endnotes} 
+DeclareLyXModule[endnotes.sty]{Endnotes} 
 \end_layout
 
 \begin_layout Standard
 The argument in square brackets is optional: It declares any LaTeX packages
  on which the module depends.
- The two mandatory arguments, in curly brackets, are a short description
- of the module and the name of the module, as they should appear in 
+ The mandatory argument, in curly brackets, is the name of the module, as
+ it should appear in 
 \family sans
 Document\SpecialChar \menuseparator
 Settings
 \family default
 .
+ LyX uses the name to identify the module, so it should be unique.
+\end_layout
+
+\begin_layout Standard
+The module declaration should then be followed by lines like the following:
+\end_layout
+
+\begin_layout LyX-Code
+#DescriptionBegin 
+\end_layout
+
+\begin_layout LyX-Code
+#Adds an endnote command, in addition to footnotes.
  
 \end_layout
 
+\begin_layout LyX-Code
+#You will need to add  
+\backslash
+theendnotes in ERT where you 
+\end_layout
+
+\begin_layout LyX-Code
+#want the endnotes to appear.
+ 
+\end_layout
+
+\begin_layout LyX-Code
+#DescriptionEnd 
+\end_layout
+
+\begin_layout LyX-Code
+#Requires: Some Module | Some Other Module 
+\end_layout
+
+\begin_layout LyX-Code
+#Excludes: Bad Module 
+\end_layout
+
+\begin_layout Standard
+The description is used in 
+\family sans
+Document\SpecialChar \menuseparator
+Settings
+\family default
+ to provide the user with information about what the module does.
+ The Requires is used to identify other modules with which this one must
+ be used; the Excludes line is used to identify modules with which this
+ one may not be used.
+ Both are optional, and, as shown, multiple modules should be separated
+ with the pipe symbol: |.
+ Note that the required modules are treated disjunctively: 
+\emph on
+at least one
+\emph default
+ of the required modules must be used.
+ Similarly, 
+\emph on
+no
+\emph default
+ excluded module may be used.
+\end_layout
+
 \begin_layout Standard
 After creating a new module, you will need to reconfigure and then restart
  LyX for it to appear in the menu.
@@ -5901,8 +5961,8 @@ OK
 It is strongly recommended that you save your work before doing so
 \emph default
 .
- In fact, it is strongly recommended that you not attempt to create or edit
- modules while simultaneously working on documents.
+ In fact, it is strongly recommended that you not attempt to edit modules
+ while simultaneously working on documents.
  Though of course the developers strive to keep LyX stable in such situations,
  syntax errors and the like in your module file could cause strange behavior.
 \end_layout
diff --git a/lib/layouts/braille.module b/lib/layouts/braille.module
index 193eb96f16..6e99ec2af7 100644
--- a/lib/layouts/braille.module
+++ b/lib/layouts/braille.module
@@ -1,5 +1,7 @@
-#\DeclareLyXModule[braille.sty]{Defines an environment to typeset Braille.}{Braille}
-
+#\DeclareLyXModule[braille.sty]{Braille}
+#DescriptionBegin
+#Defines an environment to typeset Braille.
+#DescriptionEnd
 # Author: Uwe Stöhr <uwestoehr@web.de>
 
 Format 6
diff --git a/lib/layouts/endnotes.module b/lib/layouts/endnotes.module
index 9c00b97bd5..9f71e9613e 100644
--- a/lib/layouts/endnotes.module
+++ b/lib/layouts/endnotes.module
@@ -1,4 +1,8 @@
-#\DeclareLyXModule[endnotes.sty]{Adds an endnote command, in addition to footnotes. You will need to add \theendnotes in ERT where you want the endnotes to appear.}{Endnote}
+#\DeclareLyXModule[endnotes.sty]{Endnote}
+#DescriptionBegin
+#Adds an endnote command, in addition to footnotes. You will need to add 
+#\theendnotes in ERT where you want the endnotes to appear.
+#DescriptionEnd
 
 Format 6
 
diff --git a/lib/layouts/foottoend.module b/lib/layouts/foottoend.module
index c775224431..28e8a1e866 100644
--- a/lib/layouts/foottoend.module
+++ b/lib/layouts/foottoend.module
@@ -1,4 +1,8 @@
-#\DeclareLyXModule[endnotes.sty]{Sets all footnotes as endnotes. You will need to add \theendnotes in ERT where you want the endnotes to appear.}{Foot to End}
+#\DeclareLyXModule[endnotes.sty]{Foot to End}
+#DescriptionBegin
+#Sets all footnotes as endnotes. You will need to add \theendnotes 
+#in ERT where you want the endnotes to appear.
+#DescriptionEnd
 
 Format 6
 
diff --git a/lib/layouts/hanging.module b/lib/layouts/hanging.module
index 3ac84748d5..c6c6993efe 100644
--- a/lib/layouts/hanging.module
+++ b/lib/layouts/hanging.module
@@ -1,4 +1,8 @@
-#\DeclareLyXModule{Adds an environment for hanging paragraphs.}{Hanging}
+#\DeclareLyXModule{Hanging}
+#DescriptionBegin
+#Adds an environment for hanging paragraphs.
+#DescriptionEnd
+
 #Author: Richard Heck
 
 #Hanging paragraph code adapted from hanging.sty, available at:
diff --git a/lib/layouts/linguistics.module b/lib/layouts/linguistics.module
index 9d04931d44..51b379f2b2 100644
--- a/lib/layouts/linguistics.module
+++ b/lib/layouts/linguistics.module
@@ -1,4 +1,8 @@
-#\DeclareLyXModule[covington.sty]{Defines some special environments useful for linguistics (numbered examples, glosses, semantic markup).}{Linguistics}
+#\DeclareLyXModule[covington.sty]{Linguistics}
+#DescriptionBegin
+#Defines some special environments useful for linguistics (numbered examples,
+#glosses, semantic markup).
+#DescriptionEnd
 
 # Author: Jürgen Spitzmüller <spitz@lyx.org>
 
diff --git a/lib/layouts/logicalmkup.module b/lib/layouts/logicalmkup.module
index 1d4511e89a..4add152b7e 100644
--- a/lib/layouts/logicalmkup.module
+++ b/lib/layouts/logicalmkup.module
@@ -1,4 +1,7 @@
-#\DeclareLyXModule{Defines some character styles for logical markup: noun, emph, strong, and code.}{Logical Markup}
+#\DeclareLyXModule{Logical Markup}
+#DescriptionBegin
+#Defines some character styles for logical markup: noun, emph, strong, and code.
+#DescriptionEnd
 
 # Author : Martin vermeer <martin.vermeer@hut.fi>
 
diff --git a/lib/layouts/theorems-ams-withinsec.module b/lib/layouts/theorems-ams-withinsec.module
index f13a939201..60d42f8d0b 100644
--- a/lib/layouts/theorems-ams-withinsec.module
+++ b/lib/layouts/theorems-ams-withinsec.module
@@ -1,4 +1,10 @@
-#\DeclareLyXModule{Defines theorem environments and the proof environment for use with non-AMS classes, using the extended AMS machinery. The theorems are numbered within sections. NOTE: Only one of the theorem modules should be used at a time.}{Theorems (AMS, By Section)}
+#\DeclareLyXModule{Theorems (AMS, By Section)}
+#DescriptionBegin
+#Defines theorem environments and the proof environment for use with 
+#non-AMS classes, using the extended AMS machinery. The theorems are 
+#numbered within sections. 
+#DescriptionEnd
+#Excludes: Theorems (AMS) | Theorems | Theorems (By Chapter) | Theorems (By Section)
 
 # Author: Richard Heck <rgheck@comcast.net>
 # Adapted from amsdefs.inc and amsmaths.inc
diff --git a/lib/layouts/theorems-ams.module b/lib/layouts/theorems-ams.module
index c0b6f2d73f..8ab3621b2b 100644
--- a/lib/layouts/theorems-ams.module
+++ b/lib/layouts/theorems-ams.module
@@ -1,4 +1,10 @@
-#\DeclareLyXModule{Defines theorem environments and the proof environment for use with non-AMS classes, using the extended AMS machinery. The theorems are numbered consecutively throughout the document. NOTE: Only one of the theorem modules should be used at a time.}{Theorems (AMS)}
+#\DeclareLyXModule{Theorems (AMS)}
+#DescriptionBegin
+#Defines theorem environments and the proof environment for use with 
+#non-AMS classes, using the extended AMS machinery. The theorems are 
+#numbered consecutively throughout the document. 
+#DescriptionEnd
+#Excludes: Theorems (AMS, By Section) | Theorems | Theorems (By Chapter) | Theorems (By Section)
 
 # Author: Richard Heck <rgheck@comcast.net>
 # Adapted from amsdefs.inc and amsmaths.inc
diff --git a/lib/layouts/theorems-std.module b/lib/layouts/theorems-std.module
index 4a481ef85d..43529111a5 100644
--- a/lib/layouts/theorems-std.module
+++ b/lib/layouts/theorems-std.module
@@ -1,4 +1,9 @@
-#\DeclareLyXModule{Defines some theorem environments for use with non-AMS classes. The theorems are numbered consecutively throughout the document. NOTE: Only one of the theorem modules should be used at a time.}{Theorems}
+#\DeclareLyXModule{Theorems}
+#DescriptionBegin
+#Defines some theorem environments for use with non-AMS classes. The theorems are 
+#numbered consecutively throughout the document. 
+#DescriptionEnd
+#Excludes: Theorems (AMS, By Section) | Theorems (AMS) | Theorems (By Chapter) | Theorems (By Section)
 
 # Author: Richard Heck <rgheck@comcast.net>
 # Adapted from amsmaths.inc
diff --git a/lib/layouts/theorems-withinchap.module b/lib/layouts/theorems-withinchap.module
index 8a298138aa..e69eab7a03 100644
--- a/lib/layouts/theorems-withinchap.module
+++ b/lib/layouts/theorems-withinchap.module
@@ -1,4 +1,9 @@
-#\DeclareLyXModule{Defines some theorem environments for use with non-AMS classes. The theorems are numbered within chapters of the document. NOTES: This module should therefore be used only with document classes that define a chapter environment. Only one of the theorem modules should be used at a time.}{Theorems (By Chapter)}
+#\DeclareLyXModule{Theorems (By Chapter)}
+#DescriptionBegin
+#Defines some theorem environments for use with non-AMS classes. The theorems are 
+#numbered by chapter.
+#DescriptionEnd
+#Excludes: Theorems (AMS, By Section) | Theorems (AMS) | Theorems | Theorems (By Section)
 
 # Author: Richard Heck <rgheck@comcast.net>
 # Adapted from amsmaths.inc
diff --git a/lib/layouts/theorems-withinsec.module b/lib/layouts/theorems-withinsec.module
index 2c8486424d..f0c757c89d 100644
--- a/lib/layouts/theorems-withinsec.module
+++ b/lib/layouts/theorems-withinsec.module
@@ -1,4 +1,9 @@
-#\DeclareLyXModule{Defines some theorem environments for use with non-AMS classes. The theorems are numbered within sections of the document. NOTE: Only one of the theorem modules should be used at a time.}{Theorems (By Section)}
+#\DeclareLyXModule{Theorems (By Section)}
+#DescriptionBegin
+#Defines some theorem environments for use with non-AMS classes. The theorems are 
+#numbered by section. 
+#DescriptionEnd
+#Excludes: Theorems (AMS, By Section) | Theorems (AMS) | Theorems (By Chapter) | Theorems
 
 # Author: Richard Heck <rgheck@comcast.net>
 # Adapted from amsmaths.inc
diff --git a/src/BufferParams.cpp b/src/BufferParams.cpp
index bb77a83814..9e2ff3c57e 100644
--- a/src/BufferParams.cpp
+++ b/src/BufferParams.cpp
@@ -1421,7 +1421,7 @@ void BufferParams::makeTextClass()
 						"may not be possible.\n"), from_utf8(modName));
 			frontend::Alert::warning(_("Package not available"), msg);
 		}
-		FileName layout_file = libFileSearch("layouts", lm->filename);
+		FileName layout_file = libFileSearch("layouts", lm->getFilename());
 		textClass_->read(layout_file, TextClass::MODULE);
 	}
 }
diff --git a/src/ModuleList.cpp b/src/ModuleList.cpp
index d1ff3bee0a..bd035f4966 100644
--- a/src/ModuleList.cpp
+++ b/src/ModuleList.cpp
@@ -35,8 +35,11 @@ ModuleList moduleList;
 
 
 LyXModule::LyXModule(string const & n, string const & f, 
-	                   string const & d, vector<string> const & p) : 
-	name(n), filename(f), description(d), packageList(p), checked(false)
+	                   string const & d, vector<string> const & p,
+	                   vector<string> const & r, vector<string> const & e):
+	name(n), filename(f), description(d), 
+	packageList(p), requiredModules(r), excludedModules(e),
+	checked(false)
 {}
 
 
@@ -64,7 +67,7 @@ class ModuleSorter
 public:
 	int operator()(LyXModule const & lm1, LyXModule const & lm2) const
 	{
-		return lm1.name < lm2.name;
+		return lm1.getName() < lm2.getName();
 	}
 };
 
@@ -123,17 +126,37 @@ bool ModuleList::load()
 			//FIXME Add packages
 			if (!lex.next())
 				break;
-			string packages = lex.getString();
-			LYXERR(Debug::TCLASS, "Packages: " << packages);
+			string str = lex.getString();
+			LYXERR(Debug::TCLASS, "Packages: " << str);
 			vector<string> pkgs;
-			while (!packages.empty()) {
+			while (!str.empty()) {
 				string p;
-				packages = split(packages, p, ',');
+				str = split(str, p, ',');
 				pkgs.push_back(p);
 			}
+			if (!lex.next())
+				break;
+			str = lex.getString();
+			LYXERR(Debug::TCLASS, "Required: " << str);
+			vector<string> req;
+			while (!str.empty()) {
+				string p;
+				str = split(str, p, '|');
+				req.push_back(p);
+			}
+			if (!lex.next())
+				break;
+			str = lex.getString();
+			LYXERR(Debug::TCLASS, "Excluded: " << str);
+			vector<string> exc;
+			while (!str.empty()) {
+				string p;
+				str = split(str, p, '|');
+				exc.push_back(p);
+			}
 			// This code is run when we have
-			// modName, fname, desc, and pkgs
-			addLayoutModule(modName, fname, desc, pkgs);
+			// modName, fname, desc, pkgs, req, and exc
+			addLayoutModule(modName, fname, desc, pkgs, req, exc);
 		} // end switch
 	} //end while
 	
@@ -147,9 +170,10 @@ bool ModuleList::load()
 
 void ModuleList::addLayoutModule(string const & moduleName, 
 	string const & filename, string const & description,
-	vector<string> const & pkgs)
+	vector<string> const & pkgs, vector<string> const & req,
+	vector<string> const & exc)
 {
-	LyXModule lm(moduleName, filename, description, pkgs);
+	LyXModule lm(moduleName, filename, description, pkgs, req, exc);
 	modlist_.push_back(lm);
 }
 
@@ -182,7 +206,7 @@ LyXModule * ModuleList::operator[](string const & str)
 {
 	LyXModuleList::iterator it = modlist_.begin();
 	for (; it != modlist_.end(); ++it)
-		if (it->name == str) {
+		if (it->getName() == str) {
 			LyXModule & mod = *it;
 			return &mod;
 		}
diff --git a/src/ModuleList.h b/src/ModuleList.h
index 5c22db3036..e0e52f72ee 100644
--- a/src/ModuleList.h
+++ b/src/ModuleList.h
@@ -29,9 +29,28 @@ class LyXModule {
 public:
 	///
 	LyXModule(std::string const & n, std::string const & f, 
-	          std::string const & d, std::vector<std::string> const & p);
+	          std::string const & d, std::vector<std::string> const & p,
+	          std::vector<std::string> const & r, 
+	          std::vector<std::string> const & e);
 	/// whether the required packages are available
 	bool isAvailable();
+	///
+	std::string const & getName() const { return name; }
+	///
+	std::string const & getFilename() const { return filename; }
+	///
+	std::string const & getDescription() const { return description; }
+	///
+	std::vector<std::string> const & getPackageList() const
+		{ return packageList; }
+	///
+	std::vector<std::string> const & getRequiredModules() const 
+		{ return requiredModules; }
+	/// Modules this one excludes: the list should be treated disjunctively
+	std::vector<std::string> const & getExcludedModules() const 
+		{ return excludedModules; }
+	
+private:
 	/// what appears in the ui
 	std::string name;
 	/// the filename, without any path
@@ -40,7 +59,10 @@ public:
 	std::string description;
 	/// the LaTeX packages on which this depends, if any (not implemented)
 	std::vector<std::string> packageList;
-private:
+	/// Modules this one requires: at least one
+	std::vector<std::string> requiredModules;
+	/// Modules this one excludes: none of these
+	std::vector<std::string> excludedModules;
 	///
 	bool checked;
 	///
@@ -59,10 +81,6 @@ public:
 	ModuleList() {}
 	/// reads the modules from a file generated by configure.py
 	bool load();
-	/// add a module to the list
-	void addLayoutModule(std::string const & name,
-		std::string const & filename, std::string const & description,
-		std::vector<std::string> const & packages);
 	///
 	LyXModuleList::const_iterator begin() const;
 	///
@@ -79,8 +97,12 @@ public:
 private:
 	/// noncopyable
 	ModuleList(ModuleList const &);
+	///
 	void operator=(ModuleList const &);
-
+	/// add a module to the list
+	void addLayoutModule(std::string const &, std::string const &, 
+		std::string const &, std::vector<std::string> const &,
+		std::vector<std::string> const &, std::vector<std::string> const &);
 	///
 	std::vector<LyXModule> modlist_;
 };
diff --git a/src/frontends/qt4/GuiDocument.cpp b/src/frontends/qt4/GuiDocument.cpp
index ad08b559da..4586ba1972 100644
--- a/src/frontends/qt4/GuiDocument.cpp
+++ b/src/frontends/qt4/GuiDocument.cpp
@@ -134,6 +134,122 @@ vector<pair<string, lyx::docstring> > pagestyles;
 namespace lyx {
 namespace frontend {
 
+namespace {
+	vector<string> getRequiredList(string const & modName) 
+	{
+		LyXModule const * const mod = moduleList[modName];
+		if (!mod)
+			return vector<string>(); //empty such thing
+		return mod->getRequiredModules();
+	}
+
+
+	vector<string> getExcludedList(string const & modName)
+	{
+		LyXModule const * const mod = moduleList[modName];
+		if (!mod)
+			return vector<string>(); //empty such thing
+		return mod->getExcludedModules();
+	}
+
+
+	docstring getModuleDescription(string const & modName)
+	{
+		LyXModule const * const mod = moduleList[modName];
+		if (!mod)
+			return _("Module not found!");
+		return from_ascii(mod->getDescription());
+	}
+
+
+	vector<string> getPackageList(string const & modName)
+	{
+		LyXModule const * const mod = moduleList[modName];
+		if (!mod)
+			return vector<string>(); //empty such thing
+		return mod->getPackageList();
+	}
+
+
+	bool isModuleAvailable(string const & modName)
+	{
+		LyXModule * mod = moduleList[modName];
+		if (!mod)
+			return false;
+		return mod->isAvailable();
+	}
+} //anonymous namespace
+
+
+ModuleSelMan::ModuleSelMan(
+	QListView * availableLV, 
+	QListView * selectedLV,
+	QPushButton * addPB, 
+	QPushButton * delPB, 
+	QPushButton * upPB, 
+	QPushButton * downPB,
+	QStringListModel * availableModel,
+	QStringListModel * selectedModel) :
+GuiSelectionManager(availableLV, selectedLV, addPB, delPB,
+                    upPB, downPB, availableModel, selectedModel) 
+{}
+	
+	
+void ModuleSelMan::updateAddPB() 
+{
+	int const arows = availableLV->model()->rowCount();
+	QModelIndexList const availSels = 
+			availableLV->selectionModel()->selectedIndexes();
+	if (arows == 0 || availSels.isEmpty()  || isSelected(availSels.first())) {
+		addPB->setEnabled(false);
+		return;
+	}
+	
+	QModelIndex const & idx = availableLV->selectionModel()->currentIndex();
+	string const modName = fromqstr(idx.data().toString());
+	vector<string> reqs = getRequiredList(modName);
+	vector<string> excl = getExcludedList(modName);
+	
+	if (reqs.empty() && excl.empty()) {
+		addPB->setEnabled(true);
+		return;
+	}
+
+	QStringList const & qsl = selectedModel->stringList();
+	
+	//Check whether some required module is available
+	if (!reqs.empty()) {
+		bool foundOne = false;
+		vector<string>::const_iterator it  = reqs.begin();
+		vector<string>::const_iterator end = reqs.end();
+		for (; it != end; ++it) {
+			if (qsl.contains(toqstr(*it))) {
+				foundOne = true;
+				break;
+			}
+		}
+		if (!foundOne) {
+			addPB->setEnabled(false);
+			return;
+		}
+	}
+	
+	//Check whether any excluded module is being used
+	if (!excl.empty()) {
+		vector<string>::const_iterator it  = excl.begin();
+		vector<string>::const_iterator end = excl.end();
+		for (; it != end; ++it) {
+			if (qsl.contains(toqstr(*it))) {
+				addPB->setEnabled(false);
+				return;
+			}
+		}
+	}
+
+	addPB->setEnabled(true);
+}
+
+
 /////////////////////////////////////////////////////////////////////
 //
 // PreambleModule
@@ -566,7 +682,7 @@ GuiDocument::GuiDocument(GuiView & lv)
 		this, SLOT(classChanged()));
 	
 	selectionManager = 
-		new GuiSelectionManager(latexModule->availableLV, latexModule->selectedLV, 
+		new ModuleSelMan(latexModule->availableLV, latexModule->selectedLV, 
 			latexModule->addPB, latexModule->deletePB, 
 	 		latexModule->upPB, latexModule->downPB, 
 			availableModel(), selectedModel());
@@ -920,46 +1036,77 @@ void GuiDocument::classChanged()
 }
 
 
+namespace {
+	//This is an insanely complicated attempt to make this sort of thing
+	//work with RTL languages.
+	docstring formatStrVec(vector<string> const & v, docstring const & s) 
+	{
+		//this mess formats the list as "v[0], v[1], ..., [s] v[n]"
+		int const vSize = v.size();
+		if (v.size() == 0)
+			return docstring();
+		else if (v.size() == 1) 
+			return from_ascii(v[0]);
+		else if (v.size() == 2) {
+			docstring retval = _("%1$s and %2$s");
+			retval = subst(retval, _("and"), s);
+			return bformat(retval, from_ascii(v[0]), from_ascii(v[1]));
+		}
+		//The idea here is to format all but the last two items...
+		docstring t2 = _("%1$s, %2$s");
+		docstring retval = from_ascii(v[0]);
+		for (int i = 1; i < vSize - 2; ++i)
+			retval = bformat(t2, retval, from_ascii(v[i])); 
+		//...and then to  plug them, and the last two, into this schema
+		docstring t = _("%1$s, %2$s, and %3$s");
+		t = subst(t, _("and"), s);
+		return bformat(t, retval, from_ascii(v[vSize - 2]), from_ascii(v[vSize - 1]));
+	}
+}
+
+
 void GuiDocument::updateModuleInfo()
 {
 	selectionManager->update();
 	//Module description
 	QListView const * const lv = selectionManager->selectedFocused() ?
 	                             latexModule->selectedLV :
-			latexModule->availableLV;
+	                             latexModule->availableLV;
 	if (lv->selectionModel()->selectedIndexes().isEmpty())
 		latexModule->infoML->document()->clear();
 	else {
-		QModelIndex const idx = lv->selectionModel()->currentIndex();
+		QModelIndex const & idx = lv->selectionModel()->currentIndex();
 		string const modName = fromqstr(idx.data().toString());
-		string desc = getModuleDescription(modName);
+		docstring desc = getModuleDescription(modName);
+
 		vector<string> pkgList = getPackageList(modName);
-		string pkgdesc;
-		//this mess formats the package list as "pkg1, pkg2, and pkg3"
-		int const pkgListSize = pkgList.size();
-		for (int i = 0; i < pkgListSize; ++i) {
-			if (i == 1) {
-				if (i == pkgListSize - 1) //last element
-					pkgdesc += " and ";
-				else
-					pkgdesc += ", ";
-			} else if (i > 1) {
-				if (i == pkgListSize - 1) //last element
-					pkgdesc += ", and ";
-				else
-					pkgdesc += ", ";
-			}
-			pkgdesc += pkgList[i];
-		}
+		docstring pkgdesc = formatStrVec(pkgList, _("and"));
 		if (!pkgdesc.empty()) {
 			if (!desc.empty())
-				desc += " ";
-			desc += ("Requires " + pkgdesc + ".");
+				desc += "\n";
+			desc += bformat(_("Package(s) required: %1$s."), pkgdesc);
 		}
+
+		pkgList = getRequiredList(modName);
+		pkgdesc = formatStrVec(pkgList, _("or"));
+		if (!pkgdesc.empty()) {
+			if (!desc.empty())
+				desc += "\n";
+			desc += bformat(_("Module required: %1$s."), pkgdesc);
+		}
+
+		pkgList = getExcludedList(modName);
+		pkgdesc = formatStrVec(pkgList, _( "and"));
+		if (!pkgdesc.empty()) {
+			if (!desc.empty())
+				desc += "\n";
+			desc += bformat(_("Modules excluded: %1$s."), pkgdesc);
+		}
+
 		if (!isModuleAvailable(modName)) {
 			if (!desc.empty())
 				desc += "\n";
-			desc += "WARNING: Some packages are unavailable!";
+			desc += _("WARNING: Some packages are unavailable!");
 		}
 		latexModule->infoML->document()->setPlainText(toqstr(desc));
 	}
@@ -1631,6 +1778,10 @@ void GuiDocument::updateContents()
 	it = selMods.begin();
 	for (; it != selMods.end(); ++it)
 		strlist2.push_back(toqstr(*it));
+	//FIXME It'd be nice to make sure here that the selected
+	//modules are consistent: That required modules are actually
+	//selected, and that we don't have conflicts. If so, we could
+	//at least pop up a warning.
 	selected_model_.setStringList(strlist2);
 
 	updateParams(bp_);
@@ -1680,7 +1831,7 @@ BufferId GuiDocument::id() const
 }
 
 
-vector<string> GuiDocument::getModuleNames()
+vector<string> const & GuiDocument::getModuleNames()
 {
 	return moduleNames_;
 }
@@ -1692,33 +1843,6 @@ vector<string> const & GuiDocument::getSelectedModules()
 }
 
 
-string GuiDocument::getModuleDescription(string const & modName) const
-{
-	LyXModule const * const mod = moduleList[modName];
-	if (!mod)
-		return string("Module not found!");
-	return mod->description;
-}
-
-
-vector<string> GuiDocument::getPackageList(string const & modName) const
-{
-	LyXModule const * const mod = moduleList[modName];
-	if (!mod)
-		return vector<string>(); //empty such thing
-	return mod->packageList;
-}
-
-
-bool GuiDocument::isModuleAvailable(string const & modName) const
-{
-	LyXModule * mod = moduleList[modName];
-	if (!mod)
-		return false;
-	return mod->isAvailable();
-}
-
-
 TextClass const & GuiDocument::textClass() const
 {
 	return textclasslist[bp_.getBaseClass()];
@@ -1840,7 +1964,7 @@ void GuiDocument::loadModuleNames ()
 	moduleNames_.clear();
 	LyXModuleList::const_iterator it = moduleList.begin();
 	for (; it != moduleList.end(); ++it)
-		moduleNames_.push_back(it->name);
+		moduleNames_.push_back(it->getName());
 	if (!moduleNames_.empty())
 		sort(moduleNames_.begin(), moduleNames_.end());
 }
diff --git a/src/frontends/qt4/GuiDocument.h b/src/frontends/qt4/GuiDocument.h
index 90a93f8314..a0fd852563 100644
--- a/src/frontends/qt4/GuiDocument.h
+++ b/src/frontends/qt4/GuiDocument.h
@@ -67,6 +67,24 @@ public:
 };
 
 
+class ModuleSelMan : public GuiSelectionManager 
+{
+public:
+	ModuleSelMan(
+		QListView * availableLV, 
+		QListView * selectedLV,
+		QPushButton * addPB, 
+		QPushButton * delPB, 
+		QPushButton * upPB, 
+		QPushButton * downPB,
+		QStringListModel * availableModel,
+		QStringListModel * selectedModel);
+private:
+	///
+	virtual void updateAddPB();
+};
+
+
 class GuiDocument : public GuiDialog, public Ui::DocumentUi
 {
 	Q_OBJECT
@@ -178,16 +196,10 @@ protected:
 	///
 	BufferId id() const;
 	/// List of available modules
-	std::vector<std::string> getModuleNames();
+	std::vector<std::string> const & getModuleNames();
 	/// Modules in use in current buffer
 	std::vector<std::string> const & getSelectedModules();
 	///
-	std::string getModuleDescription(std::string const & modName) const;
-	///
-	std::vector<std::string> getPackageList(std::string const & modName) const;
-	///
-	bool isModuleAvailable(std::string const & modName) const;
-	///
 	void setLanguage() const;
 	///
 	void saveAsDefault() const;
diff --git a/src/frontends/qt4/GuiSelectionManager.cpp b/src/frontends/qt4/GuiSelectionManager.cpp
index 7dcf33fb03..88946f501e 100644
--- a/src/frontends/qt4/GuiSelectionManager.cpp
+++ b/src/frontends/qt4/GuiSelectionManager.cpp
@@ -68,6 +68,15 @@ GuiSelectionManager::GuiSelectionManager(
 
 
 void GuiSelectionManager::update()
+{
+	updateAddPB();
+	updateDelPB();
+	updateDownPB();
+	updateUpPB();
+}
+
+
+void GuiSelectionManager::updateAddPB()
 {
 	int const arows = availableLV->model()->rowCount();
 	QModelIndexList const availSels = 
@@ -75,17 +84,38 @@ void GuiSelectionManager::update()
 	addPB->setEnabled(arows > 0 &&
 		!availSels.isEmpty() &&
 		!isSelected(availSels.first()));
-	
+}
+
+
+void GuiSelectionManager::updateDelPB()
+{
 	int const srows = selectedLV->model()->rowCount();
 	QModelIndexList const selSels = 
 		selectedLV->selectionModel()->selectedIndexes();
 	int const sel_nr = 	selSels.empty() ? -1 : selSels.first().row();
 	deletePB->setEnabled(sel_nr >= 0);
-	upPB->setEnabled(sel_nr > 0);
-	downPB->setEnabled(sel_nr >= 0 && sel_nr < srows - 1);
 }
 
 
+void GuiSelectionManager::updateDownPB()
+{
+	int const srows = selectedLV->model()->rowCount();
+	QModelIndexList const selSels = 
+			selectedLV->selectionModel()->selectedIndexes();
+	int const sel_nr = 	selSels.empty() ? -1 : selSels.first().row();
+	upPB->setEnabled(sel_nr > 0);
+}
+
+
+void GuiSelectionManager::updateUpPB()
+{
+	int const srows = selectedLV->model()->rowCount();
+	QModelIndexList const selSels = 
+			selectedLV->selectionModel()->selectedIndexes();
+	int const sel_nr = 	selSels.empty() ? -1 : selSels.first().row();
+	downPB->setEnabled(sel_nr >= 0 && sel_nr < srows - 1);
+}
+
 bool GuiSelectionManager::isSelected(const QModelIndex & idx)
 {
 	QString const str = idx.data().toString();
@@ -211,7 +241,7 @@ void GuiSelectionManager::availableLV_clicked(const QModelIndex &)
 
 void GuiSelectionManager::availableLV_doubleClicked(const QModelIndex & idx)
 {
-	if (isSelected(idx))
+	if (isSelected(idx) || !addPB->isEnabled())
 		return;
 	
 	if (idx.isValid())
diff --git a/src/frontends/qt4/GuiSelectionManager.h b/src/frontends/qt4/GuiSelectionManager.h
index ac4671be45..fa176327e7 100644
--- a/src/frontends/qt4/GuiSelectionManager.h
+++ b/src/frontends/qt4/GuiSelectionManager.h
@@ -50,6 +50,8 @@ public:
 	/// Sets the state of the various push buttons, depending upon the
 	/// state of the widgets. (E.g., "delete" is enabled only if the
 	/// selection is non-empty.)
+	/// Note: this is separated out into updateAddPB(), etc, below, 
+	/// for easy over-riding of these functions.
 	void update();
 	
 	/// Not strictly a matter of focus, which may be elsewhere, but
@@ -79,6 +81,22 @@ protected:
 	///Given a QModelIndex from availableLV, determines whether it has
 	///been selected (i.e., is also in selectedLV).
 	bool isSelected(const QModelIndex & idx);
+	///
+	QListView * availableLV;
+	///
+	QListView * selectedLV;
+	///
+	QPushButton * addPB;
+	///
+	QPushButton * deletePB; 
+	///
+	QPushButton * upPB;
+	///
+	QPushButton * downPB;
+	///
+	QStringListModel * availableModel;
+	///
+	QStringListModel * selectedModel;
 
 protected Q_SLOTS:
 	///
@@ -103,15 +121,14 @@ protected Q_SLOTS:
 	bool eventFilter(QObject *, QEvent *);
 
 private:
-	QListView * availableLV;
-	QListView * selectedLV;
-	QPushButton * addPB;
-	QPushButton * deletePB; 
-	QPushButton * upPB;
-	QPushButton * downPB;
-	QStringListModel * availableModel;
-	QStringListModel * selectedModel;
-	//Dialog::View * dialog;
+	///
+	virtual void updateAddPB();
+	///
+	virtual void updateDelPB();
+	///
+	virtual void updateDownPB();
+	///
+	virtual void updateUpPB();
 	
 	bool selectedHasFocus_;
 };