Time for an 2014 update…

Task/Fibonacci-sequence/GML/fibonacci-sequence.gml

@@ -0,0 +1,25 @@
+///fibonacci(n)
+//Returns the nth fibonacci number
+
+var n, numb;
+n = argument0;
+
+if (n == 0)
+    {
+    numb = 0;
+    }
+else
+    {
+    var fm2, fm1;
+    fm2 = 0;
+    fm1 = 1;
+    numb = 1;
+    repeat(n-1)
+        {
+        numb = fm2+fm1;
+        fm2 = fm1;
+        fm1 = numb;
+        }
+    }
+
+return numb;