diff --git a/diamond.lisp b/diamond.lisp
new file mode 100644
index 0000000..872bf2f
--- /dev/null
+++ b/diamond.lisp
@@ -0,0 +1,95 @@
+;;;;
+;;;; An implementation of the diamond landscape generation algorithm.
+;;;; Daniel Vedder, 14/9/2018
+;;;;
+
+(defconstant WORLD-SIZE 10)
+(defvar *size* (1+ (expt 2 WORLD-SIZE)))
+(defvar *base-height* 50)
+
+(defvar *world* NIL)
+
+;;; WORLD RELATED FUNCTIONS
+
+(defun init-matrix (&optional (size *size*))
+	(unless (integerp (log (1- size) 2)) (error "~&Unusable size"))
+	(format t "~&Creating a ~Sx~S world matrix." size size)
+	(do ((y 0 (1+ y)) (world NIL) (row NIL NIL))
+		((= y size) world)
+		(dotimes (x size)
+			(setf row (cons NIL row)))
+		(setf world (append world (list row)))))
+
+(defun getv (x y &optional (world *world*))
+	"Return the height value at the given coordinates or NIL if out of bounds"
+	(unless (or (< x 0) (< y 0) (> x (length world)) (> y (length world)))
+		(nth x (nth y world))))
+
+(defun setv (x y value &optional (world *world*))
+	"Set the height value at the given coordinates if possible"
+	(unless (or (< x 0) (< y 0) (> x (length world)) (> y (length world)))
+		(setf (nth x (nth y world)) value)))
+
+(defun dist (x1 y1 x2 y2)
+	"Calculate the distance between these two points"
+	(max (abs (- x1 x2)) (abs (- y1 y2))))
+
+(defun print-world (&optional (world *world*) (stream t))
+	(dolist (row world)
+		;; XXX This would be quicker with (string-from-list), but I
+		;; don't want to use util.lisp just yet
+		(do ((x 0 (1+ x)) (xstr ""))
+			((= x (length world)) (format stream "~&~A~%" xstr))
+			(setf xstr (concatenate 'string xstr (unless (= x 0) ",")
+						   (format NIL "~S" (nth x row)))))))
+
+(defun save-topography (file-name &optional (world *world*))
+	"Save the world topography as a csv file"
+	(with-open-file (tf file-name :direction :output)
+		(print-world world tf)))
+
+;;; DIAMOND ALGORITHM FUNCTIONS
+
+(defun avg (&rest values)
+	"Calculate the average"
+	(/ (reduce #'+ values) (length values)))
+
+(defun midpoint (x1 y1 x2 y2)
+	"Calculate the midpoint displacement"
+	(let ((displacement (round (/ (dist x1 y1 x2 y2) 2))))
+		(round (+ (avg (getv x1 y1) (getv x2 y2)
+					  (if (zerop displacement) 0
+						  (- displacement (* 2 (random displacement)))))))))
+
+(defun diamond-step (&optional (world *world*) (minx 0) (miny 0)
+				   (maxx (1- (length world))) (maxy (1- (length world))))
+	"Carry out one step of the diamond algorithm"
+	(let ((xm (avg minx maxx)) (ym (avg miny maxy)))
+		(setv xm miny (midpoint minx miny maxx miny) world)
+		(setv minx ym (midpoint minx miny minx maxy) world)
+		(setv maxx ym (midpoint maxx miny maxx maxy) world)
+		(setv xm maxy (midpoint minx maxy maxx maxy) world)
+		(setv xm ym (avg (midpoint xm miny xm maxy)
+						(midpoint minx ym maxx ym))
+			world)
+		(unless (= 1 (dist minx miny xm ym))
+			(diamond-step world minx miny xm ym)
+			(diamond-step world xm miny maxx ym)
+			(diamond-step world minx ym xm maxy)
+			(diamond-step world xm ym maxx maxy))))
+
+(defun diamond (&optional (world *world*) (base-height *base-height*))
+	"Initialise and begin the diamond algorithm"
+	(setv 0 0 base-height)
+	(setv 0 (1- (length world)) base-height)
+	(setv (1- (length world)) 0 base-height)
+	(setv (1- (length world)) (1- (length world)) base-height)
+	(diamond-step world))
+
+
+(defun create-world ()
+	(setf *world* (init-matrix *size*))
+	(diamond))
+
+;; Initialize the random state (which would otherwise not be very random...)
+(setf *random-state* (make-random-state t))

diff --git a/diamond.lisp b/diamond.lisp
new file mode 100644
index 0000000..872bf2f
--- /dev/null
+++ b/diamond.lisp
@@ -0,0 +1,95 @@
+;;;;
+;;;; An implementation of the diamond landscape generation algorithm.
+;;;; Daniel Vedder, 14/9/2018
+;;;;
+
+(defconstant WORLD-SIZE 10)
+(defvar *size* (1+ (expt 2 WORLD-SIZE)))
+(defvar *base-height* 50)
+
+(defvar *world* NIL)
+
+;;; WORLD RELATED FUNCTIONS
+
+(defun init-matrix (&optional (size *size*))
+	(unless (integerp (log (1- size) 2)) (error "~&Unusable size"))
+	(format t "~&Creating a ~Sx~S world matrix." size size)
+	(do ((y 0 (1+ y)) (world NIL) (row NIL NIL))
+		((= y size) world)
+		(dotimes (x size)
+			(setf row (cons NIL row)))
+		(setf world (append world (list row)))))
+
+(defun getv (x y &optional (world *world*))
+	"Return the height value at the given coordinates or NIL if out of bounds"
+	(unless (or (< x 0) (< y 0) (> x (length world)) (> y (length world)))
+		(nth x (nth y world))))
+
+(defun setv (x y value &optional (world *world*))
+	"Set the height value at the given coordinates if possible"
+	(unless (or (< x 0) (< y 0) (> x (length world)) (> y (length world)))
+		(setf (nth x (nth y world)) value)))
+
+(defun dist (x1 y1 x2 y2)
+	"Calculate the distance between these two points"
+	(max (abs (- x1 x2)) (abs (- y1 y2))))
+
+(defun print-world (&optional (world *world*) (stream t))
+	(dolist (row world)
+		;; XXX This would be quicker with (string-from-list), but I
+		;; don't want to use util.lisp just yet
+		(do ((x 0 (1+ x)) (xstr ""))
+			((= x (length world)) (format stream "~&~A~%" xstr))
+			(setf xstr (concatenate 'string xstr (unless (= x 0) ",")
+						   (format NIL "~S" (nth x row)))))))
+
+(defun save-topography (file-name &optional (world *world*))
+	"Save the world topography as a csv file"
+	(with-open-file (tf file-name :direction :output)
+		(print-world world tf)))
+
+;;; DIAMOND ALGORITHM FUNCTIONS
+
+(defun avg (&rest values)
+	"Calculate the average"
+	(/ (reduce #'+ values) (length values)))
+
+(defun midpoint (x1 y1 x2 y2)
+	"Calculate the midpoint displacement"
+	(let ((displacement (round (/ (dist x1 y1 x2 y2) 2))))
+		(round (+ (avg (getv x1 y1) (getv x2 y2)
+					  (if (zerop displacement) 0
+						  (- displacement (* 2 (random displacement)))))))))
+
+(defun diamond-step (&optional (world *world*) (minx 0) (miny 0)
+				   (maxx (1- (length world))) (maxy (1- (length world))))
+	"Carry out one step of the diamond algorithm"
+	(let ((xm (avg minx maxx)) (ym (avg miny maxy)))
+		(setv xm miny (midpoint minx miny maxx miny) world)
+		(setv minx ym (midpoint minx miny minx maxy) world)
+		(setv maxx ym (midpoint maxx miny maxx maxy) world)
+		(setv xm maxy (midpoint minx maxy maxx maxy) world)
+		(setv xm ym (avg (midpoint xm miny xm maxy)
+						(midpoint minx ym maxx ym))
+			world)
+		(unless (= 1 (dist minx miny xm ym))
+			(diamond-step world minx miny xm ym)
+			(diamond-step world xm miny maxx ym)
+			(diamond-step world minx ym xm maxy)
+			(diamond-step world xm ym maxx maxy))))
+
+(defun diamond (&optional (world *world*) (base-height *base-height*))
+	"Initialise and begin the diamond algorithm"
+	(setv 0 0 base-height)
+	(setv 0 (1- (length world)) base-height)
+	(setv (1- (length world)) 0 base-height)
+	(setv (1- (length world)) (1- (length world)) base-height)
+	(diamond-step world))
+
+
+(defun create-world ()
+	(setf *world* (init-matrix *size*))
+	(diamond))
+
+;; Initialize the random state (which would otherwise not be very random...)
+(setf *random-state* (make-random-state t))
diff --git a/diamond_algorithm.txt b/diamond_algorithm.txt
new file mode 100644
index 0000000..68aa347
--- /dev/null
+++ b/diamond_algorithm.txt
@@ -0,0 +1,24 @@
+
+INIT
+
+X - - - X
+- - - - -
+- - - - -
+- - - - -
+X - - - X
+
+HALFSTEP
+
+X - 0 - X
+- - - - -
+0 - - - 0
+- - - - -
+X - 0 - X
+
+CENTERSTEP
+
+X - 0 - X
+- - - - -
+0 - 8 - 0
+- - - - -
+X - 0 - X