diff --git a/src/db/db/dbD25TechnologyComponent.cc b/src/db/db/dbD25TechnologyComponent.cc
index 2719bfbb7..88723050b 100644
--- a/src/db/db/dbD25TechnologyComponent.cc
+++ b/src/db/db/dbD25TechnologyComponent.cc
@@ -119,6 +119,7 @@ D25TechnologyComponent::D25TechnologyComponent ()
   //  provide some explanation for the initialization
   m_src =
     "# Provide z stack information here\n"
+    "#\n"
     "# Each line is one layer. The specification consists of a layer specification, a colon and arguments.\n"
     "# The arguments are named (like \"x=...\") or in serial. Parameters are separated by comma or blanks.\n"
     "# Named arguments are:\n"
@@ -127,7 +128,7 @@ D25TechnologyComponent::D25TechnologyComponent ()
     "#   zstop    The upper z position of the extruded layer in µm\n"
     "#   height   The height of the extruded layer in µm\n"
     "#\n"
-    "# 'height', 'zstart' and 'zstop' can be used in any combination. If no value is given for 'zstart', "
+    "# 'height', 'zstart' and 'zstop' can be used in any combination. If no value is given for 'zstart',\n"
     "# the upper level of the previous layer will be used.\n"
     "#\n"
     "# If a single unnamed parameter is given, it corresponds to 'height'. Two parameters correspond to\n"
@@ -139,6 +140,30 @@ D25TechnologyComponent::D25TechnologyComponent ()
     "#   1: zstop=1.5, zstart=0.5      # same with named parameters\n"
     "#   1: height=1.0, zstop=1.5      # same with z stop minus height\n"
     "#   1: 1.0 zstop=1.5              # same with height as unnamed parameter\n"
+    "#\n"
+    "# VARIABLES\n"
+    "#\n"
+    "# You can declare variables with:\n"
+    "#   var name = value\n"
+    "#\n"
+    "# You can use variables inside numeric expressions.\n"
+    "# Example:\n"
+    "#   var hmetal = 0.48\n"
+    "#   7/0: 0.5 0.5+hmetal*2        # 2x thick metal\n"
+    "#\n"
+    "# You cannot use variables inside layer specifications currently.\n"
+    "#\n"
+    "# CONDITIONALS\n"
+    "#\n"
+    "# You can enable or disable branches of the table using 'if', 'else', 'elseif' and 'end':\n"
+    "# Example:\n"
+    "#   var thick_m1 = true\n"
+    "#   if thickm1\n"
+    "#     1: 0.5 1.5\n"
+    "#   else\n"
+    "#     1: 0.5 1.2\n"
+    "#   end\n"
+    "\n"
   ;
 }
 
@@ -157,6 +182,9 @@ D25TechnologyComponent::compile_from_source (const std::string &src)
 
   try {
 
+    tl::Eval eval;
+    std::vector<bool> conditional_stack;
+
     std::vector<std::string> lines = tl::split (src, "\n");
     for (std::vector<std::string>::const_iterator l = lines.begin (); l != lines.end (); ++l) {
 
@@ -168,6 +196,64 @@ D25TechnologyComponent::compile_from_source (const std::string &src)
         //  ignore comments
       } else if (ex.at_end ()) {
         //  ignore empty lines
+
+      } else if (ex.test ("if")) {
+
+        tl::Expression x;
+        eval.parse (x, ex);
+        conditional_stack.push_back (x.execute ().to_bool ());
+
+        ex.expect_end ();
+
+      } else if (ex.test ("else")) {
+
+        if (conditional_stack.empty ()) {
+          throw tl::Exception (tl::to_string (tr ("'else' without 'if'")));
+        }
+
+        conditional_stack.back () = ! conditional_stack.back ();
+
+        ex.expect_end ();
+
+      } else if (ex.test ("end")) {
+
+        if (conditional_stack.empty ()) {
+          throw tl::Exception (tl::to_string (tr ("'end' without 'if'")));
+        }
+
+        conditional_stack.pop_back ();
+
+        ex.expect_end ();
+
+      } else if (ex.test ("elsif")) {
+
+        if (conditional_stack.empty ()) {
+          throw tl::Exception (tl::to_string (tr ("'elsif' without 'if'")));
+        }
+
+        tl::Expression x;
+        eval.parse (x, ex);
+        conditional_stack.back () = x.execute ().to_bool ();
+
+        ex.expect_end ();
+
+      } else if (! conditional_stack.empty () && ! conditional_stack.back ()) {
+
+        continue;
+
+      } else if (ex.test ("var")) {
+
+        std::string n;
+        ex.read_name (n);
+
+        ex.expect ("=");
+
+        tl::Expression x;
+        eval.parse (x, ex);
+        eval.set_var (n, x.execute ());
+
+        ex.expect_end ();
+
       } else {
 
         db::D25LayerInfo info;
@@ -191,16 +277,18 @@ D25TechnologyComponent::compile_from_source (const std::string &src)
             break;
           }
 
-          double pv = 0.0;
+          tl::Expression pvx;
 
           std::string pn;
           if (ex.try_read_name (pn)) {
             ex.expect ("=");
-            ex.read (pv);
+            eval.parse (pvx, ex);
           } else {
-            ex.read (pv);
+            eval.parse (pvx, ex);
           }
 
+          double pv = pvx.execute ().to_double ();
+
           ex.test (",");
 
           if (pn.empty ()) {
@@ -239,28 +327,28 @@ D25TechnologyComponent::compile_from_source (const std::string &src)
         } else if (args.size () == 1) {
           if (! h.is_nil ()) {
             if (! z0.is_nil ()) {
-              throw tl::Exception (tl::to_string (tr ("Rundundant parameters: zstart already given")));
+              throw tl::Exception (tl::to_string (tr ("Redundant parameters: zstart already given")));
             }
             if (! z1.is_nil ()) {
-              throw tl::Exception (tl::to_string (tr ("Rundundant parameters: zstop implicitly given")));
+              throw tl::Exception (tl::to_string (tr ("Redundant parameters: zstop implicitly given")));
             }
             info.set_zstart (args[0]);
             info.set_zstop (args[0] + h.to_double ());
           } else {
             if (! z1.is_nil ()) {
-              throw tl::Exception (tl::to_string (tr ("Rundundant parameters: zstop implicitly given")));
+              throw tl::Exception (tl::to_string (tr ("Redundant parameters: zstop implicitly given")));
             }
             info.set_zstop ((! z0.is_nil () ? z0.to_double () : info.zstart ()) + args[0]);
           }
         } else if (args.size () == 2) {
           if (! z0.is_nil ()) {
-            throw tl::Exception (tl::to_string (tr ("Rundundant parameters: zstart already given")));
+            throw tl::Exception (tl::to_string (tr ("Redundant parameters: zstart already given")));
           }
           if (! z1.is_nil ()) {
-            throw tl::Exception (tl::to_string (tr ("Rundundant parameters: zstop already given")));
+            throw tl::Exception (tl::to_string (tr ("Redundant parameters: zstop already given")));
           }
           if (! h.is_nil ()) {
-            throw tl::Exception (tl::to_string (tr ("Rundundant parameters: height implicitly given")));
+            throw tl::Exception (tl::to_string (tr ("Redundant parameters: height implicitly given")));
           }
           info.set_zstart (args[0]);
           info.set_zstop (args[1]);
@@ -268,12 +356,14 @@ D25TechnologyComponent::compile_from_source (const std::string &src)
           throw tl::Exception (tl::to_string (tr ("Too many parameters (max 2)")));
         }
 
-        m_layers.push_back (info);
-
       }
 
     }
 
+    if (! conditional_stack.empty ()) {
+      throw tl::Exception (tl::to_string (tr ("'if', 'else' or 'elsif' without matching 'end'")));
+    }
+
   } catch (tl::Exception &ex) {
     throw tl::Exception (ex.msg () + tl::sprintf (tl::to_string (tr (" in line %d")), current_line));
   }
diff --git a/src/laybasic/laybasic/D25TechnologyComponentEditor.ui b/src/laybasic/laybasic/D25TechnologyComponentEditor.ui
index b1901ba63..a550fe8ad 100644
--- a/src/laybasic/laybasic/D25TechnologyComponentEditor.ui
+++ b/src/laybasic/laybasic/D25TechnologyComponentEditor.ui
@@ -44,6 +44,12 @@
        <family>Monospace</family>
       </font>
      </property>
+     <property name="lineWrapMode">
+      <enum>QTextEdit::NoWrap</enum>
+     </property>
+     <property name="acceptRichText">
+      <bool>false</bool>
+     </property>
     </widget>
    </item>
   </layout>
diff --git a/src/laybasic/laybasic/syntax/d25_text.xml b/src/laybasic/laybasic/syntax/d25_text.xml
index 5e0877b74..b90e293f9 100644
--- a/src/laybasic/laybasic/syntax/d25_text.xml
+++ b/src/laybasic/laybasic/syntax/d25_text.xml
@@ -5,13 +5,33 @@
 
 	<highlighting>
 
+    <list name="Control Keywords">
+      <item> zstart </item>
+      <item> zstop </item>
+      <item> height </item>
+    </list>
+
+    <list name="Expression Keywords">
+      <item> true </item>
+      <item> false </item>
+      <item> nil </item>
+    </list>
+
 		<contexts>
 
-			<context name="Normal" attribute="Normal Text">
+			<context name="Normal" attribute="Normal Text" fallthrough="true" fallthroughContext="Error" lineEndContext="Normal">
+
+				<RegExpr attribute="Normal" String="\s*" context="#stay"/>
+
+				<StringDetect attribute="Symbol" String="var" context="Expect Assignment"/>
+				<StringDetect attribute="Symbol" String="if" context="Expression"/>
+				<StringDetect attribute="Symbol" String="elsif" context="Expression"/>
+				<StringDetect attribute="Symbol" String="else" context="Expect Lineend"/>
+				<StringDetect attribute="Symbol" String="end" context="Expect Lineend"/>
 
 				<DetectChar attribute="String" char="&quot;" context="Quoted String"/>
+				<DetectChar attribute="String" char="'" context="Apostrophed String"/>
 				<DetectChar attribute="Comment" char="#" context="Comment"/>
-				<DetectChar attribute="Raw String" char="'" context="Apostrophed String"/>
 
 				<RegExpr attribute="Normal" String=":" context="After LD"/>
 
@@ -22,22 +42,52 @@
 				<DetectChar attribute="Normal" char="/" context="#stay"/>
 				<RegExpr attribute="Raw String" String="[_a-zA-Z]\w*" context="#stay"/>
 
-				<RegExpr attribute="Error" String="[^\s]" context="Error"/>
-
 			</context>
 
 			<context name="Comment" attribute="Comment" lineEndContext="Normal">
       </context>
 
-			<context name="After LD" attribute="Normal" lineEndContext="Normal">
+			<context name="Expect Lineend" attribute="Normal" lineEndContext="Normal" fallthrough="true" fallthroughContext="Error">
+				<RegExpr attribute="Normal" String="\s*" context="#stay"/>
 				<DetectChar attribute="Comment" char="#" context="Comment"/>
+      </context>
+
+      <context name="Expression" fallthrough="true" fallthroughContext="Error" lineEndContext="Normal">
+
+				<RegExpr attribute="Normal" String="\s*" context="#stay"/>
+				<DetectChar attribute="Comment" char="#" context="Comment"/>
+
+        <keyword attribute="Symbol" String="Expression Keywords" context="#stay"/>
+        <keyword attribute="Symbol" String="Control Keywords" context="Expect Expression"/>
+
+				<DetectChar attribute="String" char="&quot;" context="Quoted String"/>
+				<DetectChar attribute="String" char="'" context="Apostrophed String"/>
+				<RegExpr attribute="Name" String="[_a-zA-Z]\w*" context="#stay"/>
 				<RegExpr attribute="Float" String="\-?[0-9]([0-9]|_[0-9])*(\.[0-9]([0-9]|_[0-9])*)?([eE]\-?[1-9]([0-9]|_[0-9])*(\.[0-9]*)?)?" context="#stay"/>
+
 				<DetectChar attribute="Normal" char="," context="#stay"/>
-				<DetectChar attribute="Normal" char="=" context="#stay"/>
-				<StringDetect attribute="Symbol" String="zstart" context="#stay"/>
-				<StringDetect attribute="Symbol" String="zstop" context="#stay"/>
-				<StringDetect attribute="Symbol" String="height" context="#stay"/>
-				<RegExpr attribute="Error" String="[^\s]" context="Error"/>
+				<DetectChar attribute="Normal" char="(" context="#stay"/>
+				<DetectChar attribute="Normal" char=")" context="#stay"/>
+				<DetectChar attribute="Normal" char="[" context="#stay"/>
+				<DetectChar attribute="Normal" char="]" context="#stay"/>
+
+				<RegExpr attribute="Normal" String="[\^\*\.\+\-%/!=&lt;&gt;&amp;|,\?:]" context="#stay"/>
+
+      </context>
+
+      <context name="Expect Expression" attribute="Normal" lineEndContext="Error" fallthrough="true" fallthroughContext="Error">
+				<RegExpr attribute="Normal" String="\s*" context="#stay"/>
+				<DetectChar attribute="Normal" char="=" context="Expression"/>
+      </context>
+
+      <context name="Expect Assignment" attribute="Normal" lineEndContext="Error" fallthrough="true" fallthroughContext="Error">
+				<RegExpr attribute="Normal" String="\s*" context="#stay"/>
+				<RegExpr attribute="Name" String="[_a-zA-Z]\w*" context="Expect Expression"/>
+      </context>
+
+			<context name="After LD" attribute="Normal" lineEndContext="Error" fallthrough="true" fallthroughContext="Expression">
+				<RegExpr attribute="Normal" String="\s*" context="#stay"/>
+				<DetectChar attribute="Comment" char="#" context="Error"/>
       </context>
 
 			<context name="Error" attribute="Error" lineEndContext="Normal">
@@ -46,19 +96,21 @@
 			<context name="Quoted String" attribute="String" lineEndContext="Error">
 				<StringDetect attribute="String" String="\\" context="#stay"/>
 				<RegExpr attribute="String" String="\\\&quot;" context="#stay"/>
-				<DetectChar char="&quot;" attribute="String" context="Normal"/>
+				<DetectChar char="&quot;" attribute="String" context="#pop"/>
 			</context>
 
 			<context name="Apostrophed String" attribute="Raw String" lineEndContext="Error">
 				<StringDetect attribute="String" String="\\" context="#stay"/>
 				<RegExpr attribute="String" String="\\\'" context="#stay"/>
-				<DetectChar char="'" attribute="Raw String" context="Normal"/>
+				<DetectChar char="'" attribute="Raw String" context="#pop"/>
 			</context>
 
     </contexts>
 
 		<itemDatas>
+
 			<itemData name="Normal Text" defStyleNum="dsNormal"/>
+			<itemData name="Name" defStyleNum="dsNormal"/>
 
 			<itemData name="Comment" defStyleNum="dsComment"/>
 			<itemData name="Float" defStyleNum="dsFloat"/>
@@ -73,4 +125,12 @@
 		</itemDatas>
 
 	</highlighting>
+
+	<general>
+		<comments>
+			<comment name="singleLine" start="#"/>
+		</comments>
+		<keywords casesensitive="1" weakDeliminator="!?"/>
+	</general>
+
 </language>
diff --git a/src/plugins/tools/view_25d/lay_plugin/layD25ViewWidget.cc b/src/plugins/tools/view_25d/lay_plugin/layD25ViewWidget.cc
index 4aaed12f1..e115b55be 100644
--- a/src/plugins/tools/view_25d/lay_plugin/layD25ViewWidget.cc
+++ b/src/plugins/tools/view_25d/lay_plugin/layD25ViewWidget.cc
@@ -246,40 +246,23 @@ D25ViewWidget::wheelEvent (QWheelEvent *event)
 
   } else {
 
-    //  compute vector of line of sight
-    std::pair<QVector3D, QVector3D> ray = camera_normal (cam_perspective () * cam_trans (), px, py);
-
-    //  by definition the ray goes through the camera position
-    QVector3D hp = hit_point_with_scene (ray.second);
+    double d = event->angleDelta ().y () * (1.0 / (90 * 16));
 
     if (! (event->modifiers () & Qt::ControlModifier)) {
 
-      //  No Ctrl is closeup
+      //  No Ctrl is "move horizontally along the azimuth axis"
 
-      double f = event->angleDelta ().y () * (1.0 / (90 * 8));
-      m_displacement += -((f / m_scale_factor) * std::min (cam_dist (), double ((cam_position () - hp).length ()))) * ray.second;
+      QMatrix4x4 t;
+      t.rotate (cam_azimuth (), 0.0, 1.0, 0.0);
+      QVector3D cd = t.inverted ().map (QVector3D (0, 0, cam_dist ()));
+
+      m_displacement += (d / m_scale_factor) * cd;
 
     } else {
 
       //  "Ctrl" is zoom
 
-      double f = exp (event->angleDelta ().y () * (1.0 / (90 * 8)));
-
-      QVector3D initial_displacement = m_displacement;
-      QVector3D displacement = m_displacement;
-
-      m_scale_factor *= f;
-      displacement += hp * (1.0 - f) / m_scale_factor;
-
-      //  normalize the scene translation so the scene does not "flee"
-
-      QMatrix4x4 ct = cam_trans ();
-      initial_displacement = ct.map (initial_displacement);
-      displacement = ct.map (displacement);
-
-      lay::normalize_scene_trans (cam_perspective (), displacement, m_scale_factor, initial_displacement.z ());
-
-      m_displacement = ct.inverted ().map (displacement);
+      m_scale_factor *= exp (d);
 
       emit scale_factor_changed (m_scale_factor);