diff --git a/Makefile b/Makefile
index 20a66362..ee6d07ab 100644
--- a/Makefile
+++ b/Makefile
@@ -81,8 +81,8 @@ IMPLS = ada awk bash basic c d chuck clojure coffee common-lisp cpp crystal cs d
 	erlang elisp elixir es6 factor forth fsharp go groovy gst guile haskell \
 	haxe io java julia js kotlin logo lua make mal ocaml matlab miniMAL \
 	nim objc objpascal perl perl6 php pil plpgsql plsql powershell ps \
-	python r racket rexx rpython ruby rust scala skew swift swift3 tcl ts vb vhdl \
-	vimscript livescript elm
+	python r racket rexx rpython ruby rust scala scm skew swift swift3 tcl \
+	ts vb vhdl vimscript livescript elm
 
 EXTENSION = .mal
 
@@ -208,6 +208,7 @@ rpython_STEP_TO_PROG = rpython/$($(1))
 ruby_STEP_TO_PROG =    ruby/$($(1)).rb
 rust_STEP_TO_PROG =    rust/target/release/$($(1))
 scala_STEP_TO_PROG =   scala/target/scala-2.11/classes/$($(1)).class
+scm_STEP_TO_PROG =     scm/$($(1)).scm
 skew_STEP_TO_PROG =    skew/$($(1)).js
 swift_STEP_TO_PROG =   swift/$($(1))
 swift3_STEP_TO_PROG =  swift3/$($(1))
diff --git a/scm/Makefile b/scm/Makefile
new file mode 100644
index 00000000..02e2630d
--- /dev/null
+++ b/scm/Makefile
@@ -0,0 +1,17 @@
+SOURCES_BASE = reader.scm printer.scm types.scm
+SOURCES_LISP = env.scm func.scm core.scm stepA_mal.scm
+SOURCES = $(SOURCES_BASE) $(SOURCES_LISP)
+
+all:
+
+clean:
+
+.PHONY: stats tests $(TESTS)
+
+stats: $(SOURCES)
+	@wc $^
+	@printf "%5s %5s %5s %s\n" `grep -E "^[[:space:]]*;|^[[:space:]]*$$" $^ | wc` "[comments/blanks]"
+stats-lisp: $(SOURCES_LISP)
+	@wc $^
+	@printf "%5s %5s %5s %s\n" `grep -E "^[[:space:]]*;|^[[:space:]]*$$" $^ | wc` "[comments/blanks]"
+
diff --git a/scm/run b/scm/run
new file mode 100755
index 00000000..258c023b
--- /dev/null
+++ b/scm/run
@@ -0,0 +1,12 @@
+#!/bin/bash
+case ${SCM_MODE:-chibi} in
+    chibi)       exec chibi-scheme   $(dirname $0)/${STEP:-stepA_mal}.scm "${@}" ;;
+    kawa)        exec kawa --r7rs    $(dirname $0)/${STEP:-stepA_mal}.scm "${@}" ;;
+    chicken)     exec csi -R r7rs -s $(dirname $0)/${STEP:-stepA_mal}.scm "${@}" ;;
+    gauche)      exec gosh           $(dirname $0)/${STEP:-stepA_mal}.scm "${@}" ;;
+    picrin)      exec picrin         $(dirname $0)/${STEP:-stepA_mal}.scm "${@}" ;;
+    sagittarius) exec sagittarius -n $(dirname $0)/${STEP:-stepA_mal}.scm "${@}" ;;
+    cyclone)     exec icyc -s        $(dirname $0)/${STEP:-stepA_mal}.scm "${@}" ;;
+    foment)      exec foment         $(dirname $0)/${STEP:-stepA_mal}.scm "${@}" ;;
+    *) echo "Invalid SCM_MODE: ${SCM_MODE}"; exit 2 ;;
+esac
diff --git a/scm/step0_repl.scm b/scm/step0_repl.scm
new file mode 100644
index 00000000..c02c11ea
--- /dev/null
+++ b/scm/step0_repl.scm
@@ -0,0 +1,33 @@
+(import (scheme base))
+(import (scheme write))
+
+(define (READ input)
+  input)
+
+(define (EVAL input)
+  input)
+
+(define (PRINT input)
+  input)
+
+(define (rep input)
+  (PRINT (EVAL (READ input))))
+
+(define (readline prompt)
+  (display prompt)
+  (flush-output-port)
+  (let ((input (read-line)))
+    (if (eof-object? input)
+        #f
+        input)))
+
+(define (main)
+  (let loop ()
+    (let ((input (readline "user> ")))
+      (when input
+        (display (rep input))
+        (newline)
+        (loop))))
+  (newline))
+
+(main)