diff --git a/collects/mzlib/cml.ss b/collects/mzlib/cml.ss
new file mode 100644
index 0000000..593822f
--- /dev/null
+++ b/collects/mzlib/cml.ss
@@ -0,0 +1,65 @@
+
+(module cml mzscheme
+  (require (lib "contract.ss"))
+
+  (define (spawn thunk)
+    (thread/suspend-to-kill thunk))
+
+  (define (sync w)
+    (object-wait-multiple #f w))
+
+  (define (channel)
+    (make-channel))
+
+  (define (channel-recv-evt ch)
+    ch)
+
+  (define (channel-send-evt ch v)
+    (make-wrapped-waitable
+     (make-channel-put-waitable ch v)
+     void))
+
+  (define (choice-evt . l)
+    (apply waitables->waitable-set l))
+
+  (define (wrap-evt w proc)
+    (make-wrapped-waitable w proc))
+
+  (define (guard-evt proc)
+    (make-guard-waitable proc))
+
+  (define (nack-guard-evt proc)
+    (make-nack-guard-waitable proc))
+
+  
+  (define (thread-done-evt th)
+    (thread-dead-waitable th))
+  
+  (define (current-time)
+    (current-seconds))
+  (define (time-evt t)
+    (make-nack-guard-waitable
+     (lambda (nack)
+       (let ([s (make-semaphore)])
+	 (thread-resume (thread/suspend-to-kill
+			 (lambda ()
+			   (sleep (max 0 (- t (current-seconds))))
+			   (semaphore-post s)))
+			(current-thread))
+	 (make-wrapped-waitable s void)))))
+
+  (provide/contract
+   (spawn ((-> any) . -> . thread?))
+   (sync (object-waitable? . -> . any))
+   (channel (-> channel?))
+   (channel-recv-evt (channel? . -> . object-waitable?))
+   (channel-send-evt (channel? any? . -> . object-waitable?))
+   (choice-evt (() (listof object-waitable?) . ->* . (object-waitable?)))
+   (wrap-evt (object-waitable? (any? . -> . any?) . -> . object-waitable?))
+   (guard-evt ((-> any?) . -> . object-waitable?))
+   (nack-guard-evt ((object-waitable? . -> . any?) . -> . object-waitable?))
+
+   (thread-done-evt (thread? . -> . object-waitable?))
+   (current-time (-> number?))
+   (time-evt (number? . -> . object-waitable?))))
+