diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..e9129b7
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+mapgen2.swf
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..827a7ef
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "third-party/as3delaunay"]
+	path = third-party/as3delaunay
+	url = git://github.com/amitp/as3delaunay.git
diff --git a/README.md b/README.md
index d87e796..134b656 100644
--- a/README.md
+++ b/README.md
@@ -31,7 +31,8 @@ available.
 
 The [full process is described here](http://www-cs-students.stanford.edu/~amitp/game-programming/polygon-map-generation/).
 
-History:
+History
+-------
 
 *   I started out with C++ code that used mountains, soil erosion, water flow, water erosion, water evaporation, volanoes, lava flow, and other physical processes to sculpt terrain expressed in a 2d array of tiles. However as described [in this blog post](http://simblob.blogspot.com/2010/06/teleological-vs-ontogenetic-map.html) I decided to abandon this approach.
 
@@ -40,7 +41,20 @@ History:
 *   The voronoi_set.as prototype worked well and I continued adding to it (instead of converting to C++). It supports terrain types: ocean, land, beach, lake, forest, swamp, desert, ice, rocky, grassland, savannah. It has rivers and roads. I decided not to convert it to C++ for now. Instead, I've refactored it into the core map generation (Map.as), display and GUI (mapgen2.as), graph representation (graph/*.as), decorative elements (Roads.as, Lava.as), and noisy edge generation (NoisyEdges.as).
 
 
-** Requirements:
+Requirements
+------------
+
+These third-party requirements have been added to the ``third-party`` directory:
 
 * [My fork of as3delaunay](http://github.com/amitp/as3delaunay)
 * The AS3 version of [de.polygonal.math.PM_PRNG.as](http://lab.polygonal.de/2007/04/21/a-good-pseudo-random-number-generator-prng/)
+
+Make sure you run ``git submodule update --init`` to check out the third-party libraries.
+
+Compiling
+---------
+
+To compile ``mapgen2.as`` to ``mapgen2.swf``, use the following command:
+
+    mxmlc -source-path+=third-party/PM_PRNG -source-path+=third-party/as3delaunay/src mapgen2.as
+
diff --git a/third-party/PM_PRNG/de/polygonal/math/PM_PRNG.as b/third-party/PM_PRNG/de/polygonal/math/PM_PRNG.as
new file mode 100644
index 0000000..d245410
--- /dev/null
+++ b/third-party/PM_PRNG/de/polygonal/math/PM_PRNG.as
@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2009 Michael Baczynski, http://www.polygonal.de
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * Implementation of the Park Miller (1988) "minimal standard" linear 
+ * congruential pseudo-random number generator.
+ * 
+ * For a full explanation visit: http://www.firstpr.com.au/dsp/rand31/
+ * 
+ * The generator uses a modulus constant (m) of 2^31 - 1 which is a
+ * Mersenne Prime number and a full-period-multiplier of 16807.
+ * Output is a 31 bit unsigned integer. The range of values output is
+ * 1 to 2,147,483,646 (2^31-1) and the seed must be in this range too.
+ * 
+ * David G. Carta's optimisation which needs only 32 bit integer math,
+ * and no division is actually *slower* in flash (both AS2 & AS3) so
+ * it's better to use the double-precision floating point version.
+ * 
+ * @author Michael Baczynski, www.polygonal.de
+ */
+package de.polygonal.math
+{
+	public class PM_PRNG
+	{
+		/**
+		 * set seed with a 31 bit unsigned integer
+		 * between 1 and 0X7FFFFFFE inclusive. don't use 0!
+		 */
+		public var seed:uint;
+		
+		public function PM_PRNG()
+		{
+			seed = 1;
+		}
+		
+		/**
+		 * provides the next pseudorandom number
+		 * as an unsigned integer (31 bits)
+		 */
+		public function nextInt():uint
+		{
+			return gen();
+		}
+		
+		/**
+		 * provides the next pseudorandom number
+		 * as a float between nearly 0 and nearly 1.0.
+		 */
+		public function nextDouble():Number
+		{
+			return (gen() / 2147483647);
+		}
+		
+		/**
+		 * provides the next pseudorandom number
+		 * as an unsigned integer (31 bits) betweeen
+		 * a given range.
+		 */
+		public function nextIntRange(min:Number, max:Number):uint
+		{
+			min -= .4999;
+			max += .4999;
+			return Math.round(min + ((max - min) * nextDouble()));
+		}
+		
+		/**
+		 * provides the next pseudorandom number
+		 * as a float between a given range.
+		 */
+		public function nextDoubleRange(min:Number, max:Number):Number
+		{
+			return min + ((max - min) * nextDouble());
+		}
+		
+		/**
+		 * generator:
+		 * new-value = (old-value * 16807) mod (2^31 - 1)
+		 */
+		private function gen():uint
+		{
+			//integer version 1, for max int 2^46 - 1 or larger.
+			return seed = (seed * 16807) % 2147483647;
+			
+			/**
+			 * integer version 2, for max int 2^31 - 1 (slowest)
+			 */
+			//var test:int = 16807 * (seed % 127773 >> 0) - 2836 * (seed / 127773 >> 0);
+			//return seed = (test > 0 ? test : test + 2147483647);
+			
+			/**
+			 * david g. carta's optimisation is 15% slower than integer version 1
+			 */
+			//var hi:uint = 16807 * (seed >> 16);
+			//var lo:uint = 16807 * (seed & 0xFFFF) + ((hi & 0x7FFF) << 16) + (hi >> 15);
+			//return seed = (lo > 0x7FFFFFFF ? lo - 0x7FFFFFFF : lo);
+		}
+	}
+}
\ No newline at end of file
diff --git a/third-party/as3delaunay b/third-party/as3delaunay
new file mode 160000
index 0000000..0c2114d
--- /dev/null
+++ b/third-party/as3delaunay
@@ -0,0 +1 @@
+Subproject commit 0c2114d805433aec93fec5c94ae429aba45300d8