diff --git a/evolve.ml b/evolve.ml
new file mode 100644
index 0000000..9a4c020
--- /dev/null
+++ b/evolve.ml
@@ -0,0 +1,167 @@
+type sensor = (int * int * int * bool)
+
+type tank = (
+  string
+  * sensor
+  * sensor
+  * sensor
+  * sensor
+  * sensor
+  * sensor
+  * sensor
+  * sensor
+  * sensor
+  * sensor
+  * string list
+)
+
+let symbols = [
+  "~";
+  "!";
+  "+";
+  "-";
+  "*";
+  "/";
+  "%";
+  "&";
+  "|";
+  "^";
+  "<<";
+  ">>";
+  ">";
+  ">=";
+  "<";
+  "<=";
+  "=";
+  "<>";
+  "abs";
+  "dup";
+  "pop";
+  "exch";
+  "if";
+  "ifelse";
+  "mset";
+  "mget";
+  "{";
+  "}";
+  "fire-ready?";
+  "fire!";
+  "set-speed!";
+  "get-turret";
+  "set-turret!";
+  "sensor?";
+  "set-led!";
+  "random";
+]
+
+let make_nucleotide () =
+  Random.int ((List.length symbols) + 360 + 360)
+  
+
+let rec make_dna = function
+  | 0 ->
+      []
+  | n ->
+      (make_nucleotide ()) :: (make_dna (n - 1))
+  
+
+let rec program_of_dna = function
+  | [] ->
+      []
+  | i :: tl ->
+      let s =
+        try
+          List.nth symbols i
+        with
+          | Failure _
+          | Invalid_argument _ ->
+              string_of_int (i - (List.length symbols) - 360)
+      in
+        s :: (program_of_dna tl)
+
+let tank_of_dna d =
+  let color_of_dna = function
+    | r :: g :: b :: tl ->
+        (tl, (Format.sprintf "%02x%02x%02x"
+                ((abs r) mod 256)
+                ((abs g) mod 256)
+                ((abs b) mod 256)))
+    | tl ->
+        (tl, "cccccc")
+  in
+  let sensor_of_dna = function
+    | a :: b :: c :: d :: tl ->
+        (tl, (a, b, c, (d != 0)))
+    | tl ->
+        (tl, (0, 0, 0, false))
+  in
+  let d, color = color_of_dna d in
+  let d, s0 = sensor_of_dna d in
+  let d, s1 = sensor_of_dna d in
+  let d, s2 = sensor_of_dna d in
+  let d, s3 = sensor_of_dna d in
+  let d, s4 = sensor_of_dna d in
+  let d, s5 = sensor_of_dna d in
+  let d, s6 = sensor_of_dna d in
+  let d, s7 = sensor_of_dna d in
+  let d, s8 = sensor_of_dna d in
+  let d, s9 = sensor_of_dna d in
+  let p = program_of_dna d in
+    (color, s0, s1, s2, s3, s4, s5, s6, s7, s8, s9, p)
+
+
+let print_tank t =
+  let print_sensor (a, b, c, d) =
+    Format.printf "Sensor: %d %d %d %d\n" a b c (if d then 1 else 0)
+  in
+    match t with
+      | (color, s0, s1, s2, s3, s4, s5, s6, s7, s8, s9, p) ->
+          Format.printf "Color: #%s\n" color;
+          print_sensor s0;
+          print_sensor s1;
+          print_sensor s2;
+          print_sensor s3;
+          print_sensor s4;
+          print_sensor s5;
+          print_sensor s6;
+          print_sensor s7;
+          print_sensor s8;
+          print_sensor s9;
+          print_endline (String.concat " " p)
+
+let write_tank i t =
+  let fnprint fn str =
+    let filename = Format.sprintf "tank.%d/%s" i fn in
+    let chan = open_out filename in
+      output_string chan str;
+      close_out chan
+  in
+  let print_sensor n (a, b, c, d) =
+    fnprint
+      (Format.sprintf "sensor%d" n)
+      (Format.sprintf "Sensor: %d %d %d %d\n" a b c (if d then 1 else 0))
+  in
+  match t with
+    | (color, s0, s1, s2, s3, s4, s5, s6, s7, s8, s9, p) ->
+        fnprint "color" color;
+        print_sensor 0 s0;
+        print_sensor 1 s1;
+        print_sensor 2 s2;
+        print_sensor 3 s3;
+        print_sensor 4 s4;
+        print_sensor 5 s5;
+        print_sensor 6 s6;
+        print_sensor 7 s7;
+        print_sensor 8 s8;
+        print_sensor 9 s9;
+        fnprint "program" (String.concat " " p)
+            
+let _ = Random.self_init ()
+
+let _ =
+  let dnas =
+    let t = Array.make 20 500 in
+      Array.map make_dna t
+  in
+  let tanks = Array.map tank_of_dna dnas in
+    Array.mapi write_tank tanks