diff --git a/scmvm.scm b/scmvm.scm
new file mode 100755
index 0000000..bffeaa3
--- /dev/null
+++ b/scmvm.scm
@@ -0,0 +1,37 @@
+#! /bin/sh
+exec guile -L . -e main -s "$0" "$@"
+!#
+(use-modules (ice-9 getopt-long)
+             (scmvm vm))
+
+(define *options-spec*
+  '((output (single-char #\o)
+            (value #t))
+    (help (single-char #\h)
+          (value #f))
+    (stack-size (value #t))
+    (memory-size (value #t))))
+
+(define parse-options
+  (lambda (options)
+    (getopt-long options *options-spec*)))
+
+(define (usage)
+  (format #t "Usage: scmvm.scm [-o outfile] mode infile
+Compile or run Scheme programs
+
+Commands:
+\tcompile\t Compile the source into an object file
+\trun\t Run the object file
+
+Yes the VM runs on Scheme, no that doesn't make any sense\n")
+  (exit))
+
+(define* (main #:optional args)
+  (define options (parse-options args))
+  (when (option-ref options 'help #f)
+    (usage)))
+
+;; Local Variables:
+;; mode: scheme
+;; End:
diff --git a/scmvm/vm.scm b/scmvm/vm.scm
index 13b5b97..3c72a3c 100644
--- a/scmvm/vm.scm
+++ b/scmvm/vm.scm
@@ -8,7 +8,7 @@
             *instruction-set* instruction-type instruction-code))
 
 ;;; Data Structures
-(define *stack-size* 1000)
+(define *stack-size* 512)
 (define *memory-size* 2048)
 
 (define* (make-stack #:optional (stack-size *stack-size*))
@@ -79,7 +79,7 @@
   (let ([bv (read-bytevector 4)])
     (bytevector-s32-ref bv 0 (native-endianness))))
 
-;;; Program execution
+;;; Instructions
 (define *instruction-set*
   '((push   #x01 i)
     (pop    #x02 o)
@@ -126,6 +126,8 @@
     [(<) <]
     [(=) =]))
 
+
+;;; Execution
 (define (jump addr)
   (seek (current-input-port) addr SEEK_SET))