diff --git a/Makefile b/Makefile
index 733b0da..07c04ff 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 ### update this to fit your system
-SCSH_PREFIX = /usr/local
+SCSH_PREFIX = /afs/wsi/i386_fbsd43/scsh-0.6.1/
 X11_PATH = /usr/X11R6
-LIB_DL = -ldl
+LIB_DL = 
 
 ### the following does not have to be changed (hopefully)
 SCHEME_INCLUDE = $(SCSH_PREFIX)/include
@@ -53,6 +53,7 @@ SCM_FILES = scheme/xlib/types.scm \
 	scheme/xlib/text.scm scheme/xlib/utility.scm \
 	scheme/xlib/visual-type.scm scheme/xlib/visual.scm \
 	scheme/xlib/window-type.scm scheme/xlib/window.scm \
+	scheme/xlib/sync-event.scm \
 	scheme/xlib/wm.scm \
 	scheme/libs/xpm.scm
 
@@ -100,3 +101,6 @@ $(SCX): $(SCX_IMAGE) main.o $(OBJECTS)
 
 clean:
 	rm -f $(SCX_VM) $(SCX) $(SCX_IMAGE) *.o c/*.o c/xlib/*.o c/libs/*.o
+
+tags:
+	find . -name "*.c" -or -name "*.h" -or -name "*.scm" | etags -
diff --git a/scheme/xlib/sync-event.scm b/scheme/xlib/sync-event.scm
new file mode 100644
index 0000000..74bc717
--- /dev/null
+++ b/scheme/xlib/sync-event.scm
@@ -0,0 +1,36 @@
+(define-record-type sync-x-event :sync-x-event
+  (really-make-sync-x-event event next)
+  sync-x-event?
+  (event sync-x-event-event)
+  (next really-next-sync-x-event really-set-next-sync-x-event))
+
+(define (make-sync-x-event event)
+  (really-make-sync-x-event event (make-placeholder)))
+
+(define (next-sync-x-event sync-x-event)
+  (placeholder-value (really-make-sync-x-event sync-x-event)))
+
+(define (set-next-sync-x-event! sync-x-event next-sync-x-event)
+  (placeholder-set! 
+   (really-next-sync-x-event sync-x-event) 
+   next-sync-x-event))
+
+(define (advance-most-recent-sync-x-event!)
+  (set! *most-recent-sync-x-event*
+	(next-sync-x-event *most-recent-sync-x-event*)))
+
+(define *most-recent-sync-x-event* (make-sync-x-event 'no-event))
+
+(define (most-recent-sync-x-event)
+  *most-recent-sync-x-event*)
+
+(define (with-sync-x-events dpy thunk)
+  (spawn (lambda ()
+	   (let lp ()
+	     (let ((next (wait-event dpy)))
+	       (set-next-sync-x-event! *most-recent-sync-x-event*
+				  (make-sync-x-event next))
+	       (advance-most-recent-sync-x-event!)))))
+  (thunk))
+	 
+	       
diff --git a/scheme/xlib/xlib-interfaces.scm b/scheme/xlib/xlib-interfaces.scm
index 59a97c4..2d46348 100644
--- a/scheme/xlib/xlib-interfaces.scm
+++ b/scheme/xlib/xlib-interfaces.scm
@@ -287,373 +287,382 @@
 	  special-pixmap:none special-pixmap:copy-from-parent
 	  special-pixmap:parent-relative))
 
-(define-interface xlib-event-interface
-  (export event-ready?
+(define-interface xlib-event-internal-interface
+  (export next-event
+	  peek-event
+	  event-ready?
 	  events-pending
 	  events-queued
-	  ((queued-mode) :syntax)
-	  next-event
-	  peek-event
-	  wait-event
-	  send-event
+	  ((queued-mode) :syntax)))
+
+(define-interface xlib-sync-x-events-interface
+  (export sync-x-event-event
+	  most-recent-sync-x-event
+	  with-sync-x-events
+	  next-sync-x-event))
+
+(define-interface xlib-event-interface
+  (export 
+   wait-event
+   send-event
 	  
-  ((event-type) :syntax)
-  any-event-type
-  any-event-serial
-  any-event-send-event?
-  any-event-display
-  any-event-window
+   ((event-type) :syntax)
+   any-event-type
+   any-event-serial
+   any-event-send-event?
+   any-event-display
+   any-event-window
 
-  create-key-event
-  key-event?
-  key-event-type
-  key-event-serial
-  key-event-send-event?
-  key-event-display
-  key-event-window
-  key-event-root
-  key-event-subwindow
-  key-event-time
-  key-event-x
-  key-event-y
-  key-event-x-root
-  key-event-y-root
-  key-event-state
-  key-event-keycode
-  key-event-same-screen?
+   create-key-event
+   key-event?
+   key-event-type
+   key-event-serial
+   key-event-send-event?
+   key-event-display
+   key-event-window
+   key-event-root
+   key-event-subwindow
+   key-event-time
+   key-event-x
+   key-event-y
+   key-event-x-root
+   key-event-y-root
+   key-event-state
+   key-event-keycode
+   key-event-same-screen?
   
-  create-button-event
-  button-event?
-  button-event-type
-  button-event-serial
-  button-event-send-event?
-  button-event-display
-  button-event-window
-  button-event-root
-  button-event-subwindow
-  button-event-time
-  button-event-x
-  button-event-y
-  button-event-x-root
-  button-event-y-root
-  button-event-state
-  button-event-button
-  button-event-same-screen?
+   create-button-event
+   button-event?
+   button-event-type
+   button-event-serial
+   button-event-send-event?
+   button-event-display
+   button-event-window
+   button-event-root
+   button-event-subwindow
+   button-event-time
+   button-event-x
+   button-event-y
+   button-event-x-root
+   button-event-y-root
+   button-event-state
+   button-event-button
+   button-event-same-screen?
 
-  create-motion-event
-  motion-event?
-  motion-event-type
-  motion-event-serial
-  motion-event-send-event?
-  motion-event-display
-  motion-event-window
-  motion-event-root
-  motion-event-subwindow
-  motion-event-time
-  motion-event-x
-  motion-event-y
-  motion-event-x-root
-  motion-event-y-root
-  motion-event-state
-  motion-event-is-hint?
-  motion-event-same-screen?
+   create-motion-event
+   motion-event?
+   motion-event-type
+   motion-event-serial
+   motion-event-send-event?
+   motion-event-display
+   motion-event-window
+   motion-event-root
+   motion-event-subwindow
+   motion-event-time
+   motion-event-x
+   motion-event-y
+   motion-event-x-root
+   motion-event-y-root
+   motion-event-state
+   motion-event-is-hint?
+   motion-event-same-screen?
   
-  create-crossing-event
-  crossing-event?
-  crossing-event-type
-  crossing-event-serial
-  crossing-event-send-event?
-  crossing-event-display
-  crossing-event-window
-  crossing-event-root
-  crossing-event-subwindow
-  crossing-event-time
-  crossing-event-x
-  crossing-event-y
-  crossing-event-x-root
-  crossing-event-y-root
-  crossing-event-mode
-  crossing-event-detail
-  crossing-event-same-screen?
-  crossing-event-focus?
-  crossing-event-state
+   create-crossing-event
+   crossing-event?
+   crossing-event-type
+   crossing-event-serial
+   crossing-event-send-event?
+   crossing-event-display
+   crossing-event-window
+   crossing-event-root
+   crossing-event-subwindow
+   crossing-event-time
+   crossing-event-x
+   crossing-event-y
+   crossing-event-x-root
+   crossing-event-y-root
+   crossing-event-mode
+   crossing-event-detail
+   crossing-event-same-screen?
+   crossing-event-focus?
+   crossing-event-state
   
-  create-focus-change-event
-  focus-change-event?
-  focus-change-event-type
-  focus-change-event-serial
-  focus-change-event-send-event?
-  focus-change-event-display
-  focus-change-event-window
-  focus-change-event-mode
-  focus-change-event-detail
+   create-focus-change-event
+   focus-change-event?
+   focus-change-event-type
+   focus-change-event-serial
+   focus-change-event-send-event?
+   focus-change-event-display
+   focus-change-event-window
+   focus-change-event-mode
+   focus-change-event-detail
   
-  create-expose-event
-  expose-event?
-  expose-event-type
-  expose-event-serial
-  expose-event-send-event?
-  expose-event-display
-  expose-event-window
-  expose-event-x
-  expose-event-y
-  expose-event-width
-  expose-event-height
-  expose-event-count
+   create-expose-event
+   expose-event?
+   expose-event-type
+   expose-event-serial
+   expose-event-send-event?
+   expose-event-display
+   expose-event-window
+   expose-event-x
+   expose-event-y
+   expose-event-width
+   expose-event-height
+   expose-event-count
 
-  create-graphics-expose-event
-  graphics-expose-event?
-  graphics-expose-event-type
-  graphics-expose-event-serial
-  graphics-expose-event-send-event?
-  graphics-expose-event-display
-  graphics-expose-event-drawable
-  graphics-expose-event-x
-  graphics-expose-event-y
-  graphics-expose-event-width
-  graphics-expose-event-height
-  graphics-expose-event-major-code
-  graphics-expose-event-minor-code
+   create-graphics-expose-event
+   graphics-expose-event?
+   graphics-expose-event-type
+   graphics-expose-event-serial
+   graphics-expose-event-send-event?
+   graphics-expose-event-display
+   graphics-expose-event-drawable
+   graphics-expose-event-x
+   graphics-expose-event-y
+   graphics-expose-event-width
+   graphics-expose-event-height
+   graphics-expose-event-major-code
+   graphics-expose-event-minor-code
 
-  create-no-expose-event
-  no-expose-event?
-  no-expose-event-type
-  no-expose-event-serial
-  no-expose-event-send-event?
-  no-expose-event-display
-  no-expose-event-drawable
-  no-expose-event-major-code
-  no-expose-event-minor-code
+   create-no-expose-event
+   no-expose-event?
+   no-expose-event-type
+   no-expose-event-serial
+   no-expose-event-send-event?
+   no-expose-event-display
+   no-expose-event-drawable
+   no-expose-event-major-code
+   no-expose-event-minor-code
 
-  create-visibility-event
-  visibility-event?
-  visibility-event-type
-  visibility-event-serial
-  visibility-event-send-event?
-  visibility-event-display
-  visibility-event-window
-  visibility-event-state
+   create-visibility-event
+   visibility-event?
+   visibility-event-type
+   visibility-event-serial
+   visibility-event-send-event?
+   visibility-event-display
+   visibility-event-window
+   visibility-event-state
 
-  create-create-window-event
-  create-window-event?
-  create-window-event-type
-  create-window-event-serial
-  create-window-event-send-event?
-  create-window-event-display
-  create-window-event-parent
-  create-window-event-window
-  create-window-event-x
-  create-window-event-y
-  create-window-event-width
-  create-window-event-height
-  create-window-event-border-width
-  create-window-event-override-redirect?
+   create-create-window-event
+   create-window-event?
+   create-window-event-type
+   create-window-event-serial
+   create-window-event-send-event?
+   create-window-event-display
+   create-window-event-parent
+   create-window-event-window
+   create-window-event-x
+   create-window-event-y
+   create-window-event-width
+   create-window-event-height
+   create-window-event-border-width
+   create-window-event-override-redirect?
 
-  create-destroy-window-event
-  destroy-window-event?
-  destroy-window-event-type
-  destroy-window-event-serial
-  destroy-window-event-send-event?
-  destroy-window-event-display
-  destroy-window-event-event
-  destroy-window-event-window
+   create-destroy-window-event
+   destroy-window-event?
+   destroy-window-event-type
+   destroy-window-event-serial
+   destroy-window-event-send-event?
+   destroy-window-event-display
+   destroy-window-event-event
+   destroy-window-event-window
 
-  create-unmap-event
-  unmap-event?
-  unmap-event-type
-  unmap-event-serial
-  unmap-event-send-event?
-  unmap-event-display
-  unmap-event-event
-  unmap-event-window
-  unmap-event-from-configure?
+   create-unmap-event
+   unmap-event?
+   unmap-event-type
+   unmap-event-serial
+   unmap-event-send-event?
+   unmap-event-display
+   unmap-event-event
+   unmap-event-window
+   unmap-event-from-configure?
   
-  create-map-event
-  map-event?
-  map-event-type
-  map-event-serial
-  map-event-send-event?
-  map-event-display
-  map-event-event
-  map-event-window
-  map-event-override-redirect?
+   create-map-event
+   map-event?
+   map-event-type
+   map-event-serial
+   map-event-send-event?
+   map-event-display
+   map-event-event
+   map-event-window
+   map-event-override-redirect?
   
-  create-map-request-event
-  map-request-event?
-  map-request-event-type
-  map-request-event-serial
-  map-request-event-send-event?
-  map-request-event-display
-  map-request-event-parent
-  map-request-event-window
+   create-map-request-event
+   map-request-event?
+   map-request-event-type
+   map-request-event-serial
+   map-request-event-send-event?
+   map-request-event-display
+   map-request-event-parent
+   map-request-event-window
 
-  create-reparent-event
-  reparent-event?
-  reparent-event-type
-  reparent-event-serial
-  reparent-event-send-event?
-  reparent-event-display
-  reparent-event-event
-  reparent-event-window
-  reparent-event-parent
-  reparent-event-x
-  reparent-event-y
-  reparent-event-override-redirect?
+   create-reparent-event
+   reparent-event?
+   reparent-event-type
+   reparent-event-serial
+   reparent-event-send-event?
+   reparent-event-display
+   reparent-event-event
+   reparent-event-window
+   reparent-event-parent
+   reparent-event-x
+   reparent-event-y
+   reparent-event-override-redirect?
   
-  create-configure-event
-  configure-event?
-  configure-event-type
-  configure-event-serial
-  configure-event-send-event?
-  configure-event-display
-  configure-event-event
-  configure-event-window
-  configure-event-x
-  configure-event-y
-  configure-event-width
-  configure-event-height
-  configure-event-border-width
-  configure-event-above
-  configure-event-override-redirect?
+   create-configure-event
+   configure-event?
+   configure-event-type
+   configure-event-serial
+   configure-event-send-event?
+   configure-event-display
+   configure-event-event
+   configure-event-window
+   configure-event-x
+   configure-event-y
+   configure-event-width
+   configure-event-height
+   configure-event-border-width
+   configure-event-above
+   configure-event-override-redirect?
 
-  create-gravity-event
-  gravity-event?
-  gravity-event-type
-  gravity-event-serial
-  gravity-event-send-event?
-  gravity-event-display
-  gravity-event-event
-  gravity-event-window
-  gravity-event-x
-  gravity-event-y
+   create-gravity-event
+   gravity-event?
+   gravity-event-type
+   gravity-event-serial
+   gravity-event-send-event?
+   gravity-event-display
+   gravity-event-event
+   gravity-event-window
+   gravity-event-x
+   gravity-event-y
   
-  create-resize-request-event
-  resize-request-event?
-  resize-request-event-type
-  resize-request-event-serial
-  resize-request-event-send-event?
-  resize-request-event-display
-  resize-request-event-window
-  resize-request-event-width
-  resize-request-event-height
+   create-resize-request-event
+   resize-request-event?
+   resize-request-event-type
+   resize-request-event-serial
+   resize-request-event-send-event?
+   resize-request-event-display
+   resize-request-event-window
+   resize-request-event-width
+   resize-request-event-height
   
-  create-configure-request-event
-  configure-request-event?
-  configure-request-event-type
-  configure-request-event-serial
-  configure-request-event-send-event?
-  configure-request-event-display
-  configure-request-event-parent
-  configure-request-event-window
-  configure-request-event-window-change-alist
+   create-configure-request-event
+   configure-request-event?
+   configure-request-event-type
+   configure-request-event-serial
+   configure-request-event-send-event?
+   configure-request-event-display
+   configure-request-event-parent
+   configure-request-event-window
+   configure-request-event-window-change-alist
 
-  create-circulate-event
-  circulate-event?
-  circulate-event-type
-  circulate-event-serial
-  circulate-event-send-event?
-  circulate-event-display
-  circulate-event-event
-  circulate-event-window
-  circulate-event-place
+   create-circulate-event
+   circulate-event?
+   circulate-event-type
+   circulate-event-serial
+   circulate-event-send-event?
+   circulate-event-display
+   circulate-event-event
+   circulate-event-window
+   circulate-event-place
 
-  create-circulate-request-event
-  circulate-request-event?
-  circulate-request-event-type
-  circulate-request-event-serial
-  circulate-request-event-send-event?
-  circulate-request-event-display
-  circulate-request-event-parent
-  circulate-request-event-window
-  circulate-request-event-place
+   create-circulate-request-event
+   circulate-request-event?
+   circulate-request-event-type
+   circulate-request-event-serial
+   circulate-request-event-send-event?
+   circulate-request-event-display
+   circulate-request-event-parent
+   circulate-request-event-window
+   circulate-request-event-place
   
-  create-property-event
-  property-event?
-  property-event-type
-  property-event-serial
-  property-event-send-event?
-  property-event-display
-  property-event-window
-  property-event-atom
-  property-event-time
-  property-event-state
+   create-property-event
+   property-event?
+   property-event-type
+   property-event-serial
+   property-event-send-event?
+   property-event-display
+   property-event-window
+   property-event-atom
+   property-event-time
+   property-event-state
 
-  create-selection-clear-event
-  selection-clear-event?
-  selection-clear-event-type
-  selection-clear-event-serial
-  selection-clear-event-send-event?
-  selection-clear-event-display
-  selection-clear-event-window
-  selection-clear-event-selection
-  selection-clear-event-time
+   create-selection-clear-event
+   selection-clear-event?
+   selection-clear-event-type
+   selection-clear-event-serial
+   selection-clear-event-send-event?
+   selection-clear-event-display
+   selection-clear-event-window
+   selection-clear-event-selection
+   selection-clear-event-time
 
-  create-selection-request-event
-  selection-request-event?
-  selection-request-event-type
-  selection-request-event-serial
-  selection-request-event-send-event?
-  selection-request-event-display
-  selection-request-event-owner
-  selection-request-event-requestor
-  selection-request-event-selection
-  selection-request-event-target
-  selection-request-event-property
-  selection-request-event-time
+   create-selection-request-event
+   selection-request-event?
+   selection-request-event-type
+   selection-request-event-serial
+   selection-request-event-send-event?
+   selection-request-event-display
+   selection-request-event-owner
+   selection-request-event-requestor
+   selection-request-event-selection
+   selection-request-event-target
+   selection-request-event-property
+   selection-request-event-time
 
-  create-selection-event
-  selection-event?
-  selection-event-type
-  selection-event-serial
-  selection-event-send-event?
-  selection-event-display
-  selection-event-requestor
-  selection-event-selection
-  selection-event-target
-  selection-event-property
-  selection-event-time
+   create-selection-event
+   selection-event?
+   selection-event-type
+   selection-event-serial
+   selection-event-send-event?
+   selection-event-display
+   selection-event-requestor
+   selection-event-selection
+   selection-event-target
+   selection-event-property
+   selection-event-time
 
-  create-colormap-event
-  colormap-event?
-  colormap-event-type
-  colormap-event-serial
-  colormap-event-send-event?
-  colormap-event-display
-  colormap-event-window
-  colormap-event-colormap
-  colormap-event-new?
-  colormap-event-state
+   create-colormap-event
+   colormap-event?
+   colormap-event-type
+   colormap-event-serial
+   colormap-event-send-event?
+   colormap-event-display
+   colormap-event-window
+   colormap-event-colormap
+   colormap-event-new?
+   colormap-event-state
 
-  create-client-message-event
-  client-message-event?
-  client-message-event-type
-  client-message-event-serial
-  client-message-event-send-event?
-  client-message-event-display
-  client-message-event-window
-  client-message-event-message-type
-  client-message-event-format
-  client-message-event-data
+   create-client-message-event
+   client-message-event?
+   client-message-event-type
+   client-message-event-serial
+   client-message-event-send-event?
+   client-message-event-display
+   client-message-event-window
+   client-message-event-message-type
+   client-message-event-format
+   client-message-event-data
   
-  create-mapping-event
-  mapping-event?
-  mapping-event-type
-  mapping-event-serial
-  mapping-event-send-event?
-  mapping-event-display
-  mapping-event-window
-  mapping-event-request
-  mapping-event-first-keycode
-  mapping-event-count
+   create-mapping-event
+   mapping-event?
+   mapping-event-type
+   mapping-event-serial
+   mapping-event-send-event?
+   mapping-event-display
+   mapping-event-window
+   mapping-event-request
+   mapping-event-first-keycode
+   mapping-event-count
 
-  create-keymap-event
-  keymap-event?
-  keymap-event-type
-  keymap-event-serial
-  keymap-event-send-event?
-  keymap-event-display
-  keymap-event-bit-vector
-))
+   create-keymap-event
+   keymap-event?
+   keymap-event-type
+   keymap-event-serial
+   keymap-event-send-event?
+   keymap-event-display
+   keymap-event-bit-vector
+   ))
 
 (define-interface xlib-text-interface
   (export text-width
@@ -909,4 +918,5 @@
 		      xlib-grab-interface
 		      xlib-visual-interface
 		      xlib-region-interface
+		      xlib-sync-x-events-interface
 		      ))
diff --git a/scheme/xlib/xlib-packages.scm b/scheme/xlib/xlib-packages.scm
index 1f6424b..f8f902f 100644
--- a/scheme/xlib/xlib-packages.scm
+++ b/scheme/xlib/xlib-packages.scm
@@ -79,7 +79,8 @@
 	finite-types)
   (files graphics))
 
-(define-structure xlib-event xlib-event-interface
+(define-structures ((xlib-event xlib-event-interface)
+		    (xlib-event-internal xlib-event-internal-interface))
   (open scsh-level-0 ;; for port->channel
 	scheme
 	external-calls
@@ -91,6 +92,14 @@
 	xlib-internal-types)
   (files event event-types))
 
+(define-structure xlib-sync-x-events xlib-sync-x-events-interface
+  (open scheme
+	placeholders
+	define-record-types
+	threads
+	xlib-event)
+  (files sync-event))
+
 (define-structure xlib-font xlib-font-interface
   (open scheme
 	signals  ;; for error
@@ -231,5 +240,6 @@
 	xlib-grab
 	xlib-visual
 	xlib-region
+	xlib-sync-x-events
 	)
   (optimize auto-integrate))