diff --git a/source/tycho/CMakeLists.txt b/source/tycho/CMakeLists.txt
index bb99487..3eb2249 100644
--- a/source/tycho/CMakeLists.txt
+++ b/source/tycho/CMakeLists.txt
@@ -29,7 +29,7 @@ add_library(
    cc_source/main.cc
    cc_source/mapprops.cc
    cc_source/menu.cc
-   cc_source/projectview.cc
+   cc_source/project.cc
    resources/resources.qrc
    ui/about.ui
    ui/license.ui
@@ -37,7 +37,7 @@ add_library(
    ui/mapview.ui
    ui/menu.ui
    ui/points.ui
-   ui/projectview.ui
+   ui/project.ui
 )
 
 set_target_properties(
diff --git a/source/tycho/bindings.json b/source/tycho/bindings.json
index fa1faa3..8983c88 100644
--- a/source/tycho/bindings.json
+++ b/source/tycho/bindings.json
@@ -6,21 +6,29 @@
       "implementationModule": "qimpl"
    },
    "objects": {
-      "ProjectModel": {
-         "type": "List",
+      "MapModel": {
+         "type": "Tree",
          "functions": {
             "open": {
                "return": "bool",
                "mut": true,
                "arguments": [{
-                  "name": "fname",
+                  "name": "path",
                   "type": "QString"
                }]
             },
             "save": {
-               "return": "void",
+               "return": "bool",
                "mut": false
             },
+            "saveAs": {
+               "return": "bool",
+               "mut": false,
+               "arguments": [{
+                  "name": "path",
+                  "type": "QString"
+               }]
+            },
             "isDirty": {
                "return": "bool",
                "mut": false
diff --git a/source/tycho/cc_headers/mapprops.h b/source/tycho/cc_headers/mapprops.h
index 2bc0bbf..196c6ca 100644
--- a/source/tycho/cc_headers/mapprops.h
+++ b/source/tycho/cc_headers/mapprops.h
@@ -4,19 +4,18 @@
 
 #include "../ui/ui_mapprops.h"
 
-class ProjectModel;
+class MapModel;
 
 class MapProps : public QDialog, private Ui::MapProps
 {
    Q_OBJECT
 
 public:
-   explicit MapProps(QSharedPointer<ProjectModel> proj,
-                     QWidget *parent = nullptr);
+   explicit MapProps(MapModel *mapModel, QWidget *parent = nullptr);
    ~MapProps();
 
 private:
-   QSharedPointer<ProjectModel> proj;
+   MapModel *mapModel;
 };
 
 // EOF
diff --git a/source/tycho/cc_headers/menu.h b/source/tycho/cc_headers/menu.h
index 00e7ebb..e6d7c55 100644
--- a/source/tycho/cc_headers/menu.h
+++ b/source/tycho/cc_headers/menu.h
@@ -5,7 +5,7 @@
 
 #include "../ui/ui_menu.h"
 
-class ProjectView;
+class Project;
 
 class Menu : public QMainWindow, private Ui::Menu
 {
@@ -27,9 +27,9 @@ protected:
    void openLicense(QWidget *parent);
 
 private:
-   ProjectView *activeProject() const;
+   Project *activeProject() const;
    QMdiSubWindow *activeSubWindow() const;
-   void addProject(ProjectView *view);
+   void addProject(Project *proj);
 };
 
 // EOF
diff --git a/source/tycho/cc_headers/project.h b/source/tycho/cc_headers/project.h
index b112cfa..7eed791 100644
--- a/source/tycho/cc_headers/project.h
+++ b/source/tycho/cc_headers/project.h
@@ -2,24 +2,50 @@
 
 #include <QMdiSubWindow>
 
-#include "bindings.h"
-#include "../ui/ui_projectview.h"
+#include "../ui/ui_project.h"
 
-class ProjectView : public QMdiSubWindow, private Ui::ProjectView
+class ProjectModel
+{
+public:
+   enum Type
+   {
+      Invalid,
+      Map,
+   };
+
+   ProjectModel(MapModel *ptr);
+   ProjectModel(ProjectModel &&o);
+   ProjectModel() = delete;
+   ProjectModel(ProjectModel &) = delete;
+   ~ProjectModel();
+
+   Type type() const;
+
+   QAbstractItemModel *getAbstract() const;
+   MapModel *getMap() const;
+
+   bool isDirty() const;
+   bool open(QString const &path);
+   bool saveAs(QString const &path) const;
+   bool save() const;
+
+private:
+   Type      modelType;
+   MapModel *modelMap;
+};
+
+class Project : public QMdiSubWindow, private Ui::Project
 {
    Q_OBJECT
 
 public:
-   explicit ProjectView(QWidget *parent = nullptr);
-   ~ProjectView();
+   explicit Project(ProjectModel &&model, QWidget *parent = nullptr);
+   ~Project();
 
-   QSharedPointer<ProjectModel> model();
+   ProjectModel model;
 
 protected:
    void closeEvent(QCloseEvent *event) override;
-
-private:
-   QSharedPointer<ProjectModel> proj;
 };
 
 // EOF
diff --git a/source/tycho/cc_headers/tycho.h b/source/tycho/cc_headers/tycho.h
index 9349140..ff4ae65 100644
--- a/source/tycho/cc_headers/tycho.h
+++ b/source/tycho/cc_headers/tycho.h
@@ -4,6 +4,8 @@
 #include <cstdint>
 #include <cstddef>
 
+#include "bindings.h"
+
 #ifdef TYCHO_DEBUG_PRINT
 #define dbgPrint(...) qDebug(__VA_ARGS__)
 #else
diff --git a/source/tycho/cc_source/mapprops.cc b/source/tycho/cc_source/mapprops.cc
index 28237e1..0bddc54 100644
--- a/source/tycho/cc_source/mapprops.cc
+++ b/source/tycho/cc_source/mapprops.cc
@@ -3,9 +3,9 @@
 
 #include <QDialogButtonBox>
 
-MapProps::MapProps(QSharedPointer<ProjectModel> _proj, QWidget *parent) :
+MapProps::MapProps(MapModel *_mapModel, QWidget *parent) :
    QDialog(parent),
-   proj(_proj)
+   mapModel(_mapModel)
 {
    setupUi(this);
 
diff --git a/source/tycho/cc_source/menu.cc b/source/tycho/cc_source/menu.cc
index 3f3ef16..4611dba 100644
--- a/source/tycho/cc_source/menu.cc
+++ b/source/tycho/cc_source/menu.cc
@@ -32,9 +32,9 @@ Menu::~Menu()
 
 void Menu::mapNew()
 {
-   QScopedPointer view{new ProjectView};
+   QScopedPointer proj{new Project(new MapModel)};
 
-   addProject(view.take());
+   addProject(proj.take());
 }
 
 void Menu::mapOpen()
@@ -46,10 +46,10 @@ void Menu::mapOpen()
          QString(),
          tr("Marathon Map files (*.scen *.sceA Map)"));
 
-   QScopedPointer view{new ProjectView};
+   QScopedPointer proj{new Project(new MapModel)};
 
-   if(view->model()->open(fname)) {
-      addProject(view.take());
+   if(proj->model.open(fname)) {
+      addProject(proj.take());
    }
 }
 
@@ -96,18 +96,18 @@ void Menu::openLicense(QWidget *parent)
 
 void Menu::openMapProperties()
 {
-   auto view = activeProject();
+   auto proj = activeProject();
 
-   if(view) {
-      MapProps props{view->model(), view};
+   if(proj && proj->model.type() == ProjectModel::Map) {
+      MapProps props{proj->model.getMap(), proj};
       props.exec();
    }
 }
 
 void Menu::updateActions()
 {
-   auto view   = activeProject();
-   bool active = view != nullptr;
+   auto proj   = activeProject();
+   bool active = proj != nullptr;
 
    actionClose->setEnabled(active);
    actionMapProps->setEnabled(active);
@@ -127,9 +127,9 @@ void Menu::closeEvent(QCloseEvent *event)
    event->accept();
 }
 
-ProjectView *Menu::activeProject() const
+Project *Menu::activeProject() const
 {
-   return qobject_cast<ProjectView *>(activeSubWindow());
+   return qobject_cast<Project *>(activeSubWindow());
 }
 
 QMdiSubWindow *Menu::activeSubWindow() const
@@ -137,9 +137,9 @@ QMdiSubWindow *Menu::activeSubWindow() const
    return mdiArea->activeSubWindow();
 }
 
-void Menu::addProject(ProjectView *view)
+void Menu::addProject(Project *proj)
 {
-   auto win = mdiArea->addSubWindow(view);
+   auto win = mdiArea->addSubWindow(proj);
 
    win->showMaximized();
 }
diff --git a/source/tycho/cc_source/project.cc b/source/tycho/cc_source/project.cc
new file mode 100644
index 0000000..c08c9cf
--- /dev/null
+++ b/source/tycho/cc_source/project.cc
@@ -0,0 +1,128 @@
+#include "tycho.h"
+#include "project.h"
+
+#include <QCloseEvent>
+#include <QMessageBox>
+
+ProjectModel::ProjectModel(MapModel *ptr) :
+   modelType(Map),
+   modelMap(ptr)
+{
+   Q_ASSERT(modelMap != nullptr);
+}
+
+ProjectModel::ProjectModel(ProjectModel &&o) :
+   modelType(o.modelType),
+   modelMap(o.modelMap)
+{
+   o.modelType = Invalid;
+}
+
+ProjectModel::~ProjectModel()
+{
+   switch(modelType) {
+      case Map: delete modelMap;
+   }
+}
+
+ProjectModel::Type ProjectModel::type() const
+{
+   return modelType;
+}
+
+QAbstractItemModel *ProjectModel::getAbstract() const
+{
+   switch(modelType) {
+      case Map: return modelMap;
+   }
+   Q_UNREACHABLE();
+}
+
+MapModel *ProjectModel::getMap() const
+{
+   return modelType == Map ? modelMap : nullptr;
+}
+
+bool ProjectModel::isDirty() const
+{
+   switch(modelType) {
+      case Map: return modelMap->isDirty();
+   }
+   Q_UNREACHABLE();
+}
+
+bool ProjectModel::open(QString const &path)
+{
+   switch(modelType) {
+      case Map: return modelMap->open(path);
+   }
+   Q_UNREACHABLE();
+}
+
+bool ProjectModel::saveAs(QString const &path) const
+{
+   switch(modelType) {
+      case Map: return modelMap->saveAs(path);
+   }
+   Q_UNREACHABLE();
+}
+
+bool ProjectModel::save() const
+{
+   switch(modelType) {
+      case Map: return modelMap->save();
+   }
+   Q_UNREACHABLE();
+}
+
+Project::Project(ProjectModel &&_model, QWidget *parent) :
+   QMdiSubWindow(parent),
+   model(std::move(_model))
+{
+   auto widget = new QWidget(this);
+
+   setupUi(widget);
+
+   setWidget(widget);
+   setAttribute(Qt::WA_DeleteOnClose);
+
+   treeView->setModel(model.getAbstract());
+
+   dbgPrintFunc();
+}
+
+Project::~Project()
+{
+   dbgPrintFunc();
+}
+
+void Project::closeEvent(QCloseEvent *event)
+{
+   if(model.isDirty()) {
+      QMessageBox msg;
+      msg.setText(tr("Do you want to save your changes to this project before closing it?"));
+      msg.setInformativeText(tr("Unsaved changes will be lost unless you save."));
+      msg.setStandardButtons(QMessageBox::Save |
+                             QMessageBox::Discard |
+                             QMessageBox::Cancel);
+      msg.setDefaultButton(QMessageBox::Save);
+
+      switch(msg.exec()) {
+         case QMessageBox::Save:
+            model.save();
+            break;
+         case QMessageBox::Discard:
+            break;
+         case QMessageBox::Cancel:
+            event->ignore();
+            return;
+         default:
+            assert(true);
+            break;
+      }
+   }
+
+   event->accept();
+}
+
+// EOF
diff --git a/source/tycho/cc_source/projectview.cc b/source/tycho/cc_source/projectview.cc
deleted file mode 100644
index bb89962..0000000
--- a/source/tycho/cc_source/projectview.cc
+++ /dev/null
@@ -1,62 +0,0 @@
-#include "tycho.h"
-#include "project.h"
-
-#include <QCloseEvent>
-#include <QMessageBox>
-
-ProjectView::ProjectView(QWidget *parent) :
-   QMdiSubWindow(parent),
-   proj(new ProjectModel)
-{
-   auto widget = new QWidget(this);
-
-   setupUi(widget);
-
-   setWidget(widget);
-   setAttribute(Qt::WA_DeleteOnClose);
-
-   listView->setModel(proj.data());
-
-   dbgPrintFunc();
-}
-
-ProjectView::~ProjectView()
-{
-   dbgPrintFunc();
-}
-
-QSharedPointer<ProjectModel> ProjectView::model()
-{
-   return proj;
-}
-
-void ProjectView::closeEvent(QCloseEvent *event)
-{
-   if(proj->isDirty()) {
-      QMessageBox msg;
-      msg.setText(tr("Do you want to save your changes to this project before closing it?"));
-      msg.setInformativeText(tr("Unsaved changes will be lost unless you save."));
-      msg.setStandardButtons(QMessageBox::Save |
-                             QMessageBox::Discard |
-                             QMessageBox::Cancel);
-      msg.setDefaultButton(QMessageBox::Save);
-
-      switch(msg.exec()) {
-         case QMessageBox::Save:
-            proj->save();
-            break;
-         case QMessageBox::Discard:
-            break;
-         case QMessageBox::Cancel:
-            event->ignore();
-            return;
-         default:
-            assert(true);
-            break;
-      }
-   }
-
-   event->accept();
-}
-
-// EOF
diff --git a/source/tycho/source/qimpl.rs b/source/tycho/source/qimpl.rs
index 42fb7f5..c649578 100644
--- a/source/tycho/source/qimpl.rs
+++ b/source/tycho/source/qimpl.rs
@@ -1,7 +1,7 @@
 //! Qt implementation.
 
-mod project;
+mod map;
 
-pub use self::project::*;
+pub use self::map::*;
 
 // EOF
diff --git a/source/tycho/source/qimpl/map.rs b/source/tycho/source/qimpl/map.rs
new file mode 100644
index 0000000..66cdb0d
--- /dev/null
+++ b/source/tycho/source/qimpl/map.rs
@@ -0,0 +1,138 @@
+//! Map model.
+
+use crate::qintr::*;
+//use memmap::Mmap;
+use maraiah::map;
+
+pub struct MapModel
+{
+   emit:  MapModelEmitter,
+   model: MapModelTree,
+}
+
+impl Drop for MapModel
+{
+   fn drop(&mut self)
+   {
+      if cfg!(debug_assertions) {
+         eprintln!("drop MapModel");
+      }
+   }
+}
+
+impl MapModelTrait for MapModel
+{
+   /// Returns a new `MapModel` instance.
+   fn new(emit: MapModelEmitter, model: MapModelTree) -> MapModel
+   {
+      if cfg!(debug_assertions) {
+         eprintln!("new MapModel");
+      }
+
+      MapModel{emit, model}
+   }
+
+   /// Returns the emitter of `self`.
+   fn emit(&mut self) -> &mut MapModelEmitter
+   {
+      &mut self.emit
+   }
+
+   /// Checks if `row` exists in the leaf `index`.
+   fn check_row(&self, index: usize, _row: usize) -> Option<usize>
+   {
+      None
+   }
+
+   /// Returns the row `index` is in.
+   fn row(&self, index: usize) -> usize
+   {
+      index
+   }
+
+   /// Returns the number of rows in `index`.
+   fn row_count(&self, index: Option<usize>) -> usize
+   {
+      match index {
+         Some(_) => 0,
+         None    => 7,
+      }
+   }
+
+   /// Returns the leaf index of `row` in the leaf `index`.
+   fn index(&self, index: Option<usize>, row: usize) -> usize
+   {
+      match index {
+         Some(_) => unreachable!(),
+         None    => row,
+      }
+   }
+
+   /// Returns the parent index of the leaf `index`, if any.
+   fn parent(&self, _index: usize) -> Option<usize>
+   {
+      // no parents!
+      None
+   }
+
+   fn row_name(&self, row: usize) -> u64
+   {
+      row as u64 + 1
+   }
+
+   fn some_number(&self, row: usize) -> u64
+   {
+      69420
+   }
+
+   /// Opens the map file at `path`.
+   fn open(&mut self, path: String) -> bool
+   {
+      if cfg!(debug_assertions) {
+         eprintln!("opening project: {}", &path);
+      }
+
+      /*
+      let fp = std::fs::File::open(path);
+      let fp = if let Ok(fp) = fp {fp} else {return false;};
+
+      let mm = unsafe {Mmap::map(&fp)};
+      let mm = if let Ok(mm) = mm {mm} else {return false;};
+
+      if let Ok(wad) = map::read(&mm) {
+         self.wad.replace(Some(wad));
+         return true;
+      }
+      */
+
+      false
+   }
+
+   /// Saves the project into the original file.
+   fn save(&self) -> bool
+   {
+      if cfg!(debug_assertions) {
+         eprintln!("saving project");
+      }
+
+      false
+   }
+
+   /// Saves the project into `path`.
+   fn save_as(&self, path: String) -> bool
+   {
+      if cfg!(debug_assertions) {
+         eprintln!("saving project as {}", path);
+      }
+
+      false
+   }
+
+   /// Returns `true` if the file has been modified from its original state.
+   fn is_dirty(&self) -> bool
+   {
+      false
+   }
+}
+
+// EOF
diff --git a/source/tycho/source/qimpl/project.rs b/source/tycho/source/qimpl/project.rs
deleted file mode 100644
index 83b6780..0000000
--- a/source/tycho/source/qimpl/project.rs
+++ /dev/null
@@ -1,88 +0,0 @@
-//! Project management.
-
-use crate::qintr::*;
-//use memmap::Mmap;
-use maraiah::map;
-
-pub struct ProjectModel
-{
-   emit: ProjectModelEmitter,
-}
-
-impl Drop for ProjectModel
-{
-   fn drop(&mut self)
-   {
-      if cfg!(debug_assertions) {
-         eprintln!("drop ProjectModel");
-      }
-   }
-}
-
-impl ProjectModelTrait for ProjectModel
-{
-   fn new(emit: ProjectModelEmitter, _: ProjectModelList) -> ProjectModel
-   {
-      if cfg!(debug_assertions) {
-         eprintln!("new ProjectModel");
-      }
-
-      ProjectModel{emit}
-   }
-
-   fn emit(&mut self) -> &mut ProjectModelEmitter
-   {
-      &mut self.emit
-   }
-
-   fn row_count(&self) -> usize
-   {
-      7
-   }
-
-   fn row_name(&self, row: usize) -> u64
-   {
-      row as u64 + 1
-   }
-
-   fn some_number(&self, row: usize) -> u64
-   {
-      69420
-   }
-
-   fn open(&mut self, path: String) -> bool
-   {
-      if cfg!(debug_assertions) {
-         eprintln!("opening project: {}", &path);
-      }
-
-      /*
-      let fp = std::fs::File::open(path);
-      let fp = if let Ok(fp) = fp {fp} else {return false;};
-
-      let mm = unsafe {Mmap::map(&fp)};
-      let mm = if let Ok(mm) = mm {mm} else {return false;};
-
-      if let Ok(wad) = map::read(&mm) {
-         self.wad.replace(Some(wad));
-         return true;
-      }
-      */
-
-      false
-   }
-
-   fn save(&self)
-   {
-      if cfg!(debug_assertions) {
-         eprintln!("saving project");
-      }
-   }
-
-   fn is_dirty(&self) -> bool
-   {
-      false
-   }
-}
-
-// EOF
diff --git a/source/tycho/ui/projectview.ui b/source/tycho/ui/project.ui
similarity index 63%
rename from source/tycho/ui/projectview.ui
rename to source/tycho/ui/project.ui
index 8cb0849..d2ec69d 100644
--- a/source/tycho/ui/projectview.ui
+++ b/source/tycho/ui/project.ui
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
- <class>ProjectView</class>
- <widget class="QWidget" name="ProjectView">
+ <class>Project</class>
+ <widget class="QWidget" name="Project">
   <property name="geometry">
    <rect>
     <x>0</x>
@@ -15,7 +15,16 @@
   </property>
   <layout class="QVBoxLayout" name="verticalLayout">
    <item>
-    <widget class="QListView" name="listView">
+    <widget class="QTreeView" name="treeView">
+     <property name="frameShape">
+      <enum>QFrame::NoFrame</enum>
+     </property>
+     <property name="frameShadow">
+      <enum>QFrame::Plain</enum>
+     </property>
+     <property name="lineWidth">
+      <number>1</number>
+     </property>
      <property name="verticalScrollBarPolicy">
       <enum>Qt::ScrollBarAlwaysOn</enum>
      </property>