diff --git a/src/alttab.c b/src/alttab.c
index 504a769..902097e 100644
--- a/src/alttab.c
+++ b/src/alttab.c
@@ -95,10 +95,6 @@ static int use_args_and_xrm(int *argc, char **argv)
     char *rm;
     char *empty = "";
     int uo;
-    Atom nwm_prop, atype;
-    unsigned char *nwm;
-    int form;
-    unsigned long remain, len;
     XrmOptionDescRec xrmTable[] = {
         {"-w", "*windowmanager", XrmoptionSepArg, NULL},
         {"-d", "*desktops", XrmoptionSepArg, NULL},
@@ -169,43 +165,20 @@ static int use_args_and_xrm(int *argc, char **argv)
 
     switch (xresource_load_int(&db, XRMAPPNAME, "windowmanager", &wmindex)) {
     case 1:
-        if (wmindex >= WM_MIN && wmindex <= WM_MAX) {
-            g.option_wm = wmindex;
-            goto wmDone;
-        } else {
+        if (wmindex < WM_MIN || wmindex > WM_MAX) {
             die(inv, "windowmanager argument range");
         }
         break;
     case 0:
         msg(0, "no WM index or unknown, guessing\n");
+        wmindex = WM_GUESS;
         break;
     case -1:
         die(inv, "windowmanager argument");
         break;
     }
-// EWMH?
-    if (ewmh_detectFeatures(&(g.ewmh))) {
-        msg(0, "EWMH-compatible WM detected: %s\n", g.ewmh.wmname);
-        g.option_wm = WM_EWMH;
-        goto wmDone;
-    }
-// ratpoison?
-    nwm_prop = XInternAtom(dpy, "_NET_WM_NAME", false);
-    if (XGetWindowProperty(dpy, root, nwm_prop, 0, MAXNAMESZ, false,
-                           AnyPropertyType, &atype, &form, &len, &remain,
-                           &nwm) == Success && nwm) {
-        msg(0, "_NET_WM_NAME root property present: %s\n", nwm);
-        if (strstr((char *)nwm, "ratpoison") != NULL) {
-            g.option_wm = WM_RATPOISON;
-            XFree(nwm);
-            goto wmDone;
-        }
-        XFree(nwm);
-    }
-    msg(0, "unknown WM, using WM_TWM\n");
-    g.option_wm = WM_TWM;
- wmDone:
-    msg(0, "WM: %d\n", g.option_wm);
+
+    initWin(wmindex);
 
     switch (xresource_load_int(&db, XRMAPPNAME, "desktops", &dsindex)) {
     case 1:
@@ -430,12 +403,6 @@ static int use_args_and_xrm(int *argc, char **argv)
         g.option_font = DEFFONT + 4;
     }
 
-// max recursion for searching windows
-// -1 is "everything"
-// in raw X this returns too much windows, "1" is probably sufficient
-// no need for an option
-    g.option_max_reclevel = (g.option_wm == WM_NO) ? 1 : -1;
-
     return 1;
 }
 
diff --git a/src/alttab.h b/src/alttab.h
index a09c821..06139a4 100644
--- a/src/alttab.h
+++ b/src/alttab.h
@@ -58,6 +58,14 @@ along with alttab.  If not, see <http://www.gnu.org/licenses/>.
 #define DEFPREVKEYKS    XK_VoidSymbol
 #define DEFNEXTKEYKS    XK_VoidSymbol
 
+#define WM_MIN          0
+#define WM_NO           0
+#define WM_EWMH         1
+#define WM_RATPOISON    2
+#define WM_TWM          3
+#define WM_MAX          3
+#define WM_GUESS        -1
+
 #include "icon.h"
 
 #ifndef COMTYPES
@@ -107,6 +115,22 @@ typedef struct PermanentWindowInfo {
     struct PermanentWindowInfo *next, *prev;
 } PermanentWindowInfo;
 
+struct WmOps {
+    bool (*probe)(void);
+    int (*startup)(void);
+    int (*winlist)(void);
+    int (*setFocus)(int idx);
+    Window (*getActiveWindow)(void);
+    bool (*skipWindowInTaskbar)(Window w);
+    bool (*skipFocusChangeEvent)(void);
+    long (*eventMask)(Window w);
+};
+
+extern struct WmOps WmNoOps;
+extern struct WmOps WmEwmhOps;
+extern struct WmOps WmRatpoisonOps;
+extern struct WmOps WmTwmOps;
+
 /*
 typedef struct SwitchMoment {
     Window prev;
@@ -126,14 +150,6 @@ typedef struct {
      * unlike g.winlist, survives uiHide */
     PermanentWindowInfo *sortlist;
     // option_* are initialized from command line arguments or X resources or defaults
-    int option_max_reclevel;    // max reclevel. -1 is "everything"
-#define WM_MIN          0
-#define WM_NO           0
-#define WM_EWMH         1
-#define WM_RATPOISON    2
-#define WM_TWM          3
-#define WM_MAX          3
-    int option_wm;
 #define DESK_MIN        0
 #define DESK_CURRENT    0
 #define DESK_ALL        1
@@ -200,6 +216,7 @@ Window getUiwin();
 void shutdownGUI(void);
 
 // windows
+void initWin(int wmindex);
 int startupWintasks();
 int addIconFromProperty(WindowInfo * wi);
 int addIconFromHints(WindowInfo * wi);
@@ -209,11 +226,6 @@ int addWindowInfo(Window win, int reclevel, int wm_id, unsigned long desktop,
 int initWinlist(void);
 void freeWinlist();
 int setFocus(int winNdx);
-int rp_startupWintasks();
-int x_initWindowsInfoRecursive(Window win, int reclevel);
-int rp_initWinlist();
-int x_setFocus(int wndx);
-int rp_setFocus(int winNdx);
 int execAndReadStdout(char *exe, char *args[], char *buf, int bufsize);
 int pulloutWindowToTop(int winNdx);
 void winPropChangeEvent(XPropertyEvent e);
@@ -221,18 +233,11 @@ void winDestroyEvent(XDestroyWindowEvent e);
 void winFocusChangeEvent(XFocusChangeEvent e);
 bool common_skipWindow(Window w, unsigned long current_desktop,
                        unsigned long window_desktop);
-void x_setCommonPropertiesForAnyWindow(Window win);
 void addToSortlist(Window w, bool to_head, bool move);
 void shutdownWin(void);
 
 /* EWHM */
-bool ewmh_detectFeatures(EwmhFeatures * e);
-Window ewmh_getActiveWindow();
-int ewmh_initWinlist();
 int ewmh_setFocus(int winNdx, Window fwin); // fwin used if non-zero
-unsigned long ewmh_getCurrentDesktop();
-unsigned long ewmh_getDesktopOfWindow(Window w);
-bool ewmh_skipWindowInTaskbar(Window w);
 
 /* RANDR */
 bool randrAvailable();
diff --git a/src/ewmh.c b/src/ewmh.c
index 6dffe13..4c036eb 100644
--- a/src/ewmh.c
+++ b/src/ewmh.c
@@ -36,6 +36,9 @@ extern int scr;
 extern Window root;
 
 // PRIVATE
+static unsigned long ewmh_getCurrentDesktop();
+static unsigned long ewmh_getDesktopOfWindow(Window w);
+static bool ewmh_skipWindowInTaskbar(Window w);
 
 //
 // returns ptr to EWMH client list and client_list_size
@@ -116,13 +119,11 @@ static int ewmh_switch_window(unsigned long window)
     return ewmh_send_wm_evt(window, "_NET_ACTIVE_WINDOW", edata);
 }
 
-// PUBLIC
-
 //
 // initialize EwmhFeatures
 // return true if usable at all
 //
-bool ewmh_detectFeatures(EwmhFeatures * e)
+static bool ewmh_detectFeatures(EwmhFeatures * e)
 {
     Window *chld_win;
     char *r;
@@ -178,7 +179,7 @@ bool ewmh_detectFeatures(EwmhFeatures * e)
 //
 // active window or 0
 //
-Window ewmh_getActiveWindow()
+static Window ewmh_getActiveWindow()
 {
     Window w = (Window) 0;
     char *awp;
@@ -196,7 +197,7 @@ Window ewmh_getActiveWindow()
 // initialize winlist, correcting sortlist
 // return 1 if ok
 //
-int ewmh_initWinlist()
+static int ewmh_initWinlist()
 {
     Window *client_list;
     unsigned long client_list_size;
@@ -254,28 +255,6 @@ int ewmh_initWinlist()
     return 1;
 }
 
-//
-// focus window in EWMH WM
-// fwin used if non-zero, winNdx otherwise
-//
-int ewmh_setFocus(int winNdx, Window fwin)
-{
-    Window win = (fwin != 0) ? fwin : g.winlist[winNdx].id;
-    msg(1, "ewmh_setFocus win 0x%lx\n", win);
-    if (fwin == 0 && g.option_desktop != DESK_CURRENT) {
-        unsigned long wdesk = g.winlist[winNdx].desktop;
-        unsigned long cdesk = ewmh_getCurrentDesktop();
-        msg(1, "ewmh_setFocus fwin 0x%lx opt %d wdesk %lu cdesk %lu\n",
-            fwin, g.option_desktop, wdesk, cdesk);
-        if (cdesk != wdesk && wdesk != DESKTOP_UNKNOWN) {
-            ewmh_switch_desktop(wdesk);
-        }
-    }
-    ewmh_switch_window(win);
-    XMapRaised(dpy, win);
-    return 1;
-}
-
 static unsigned long ewmh_getDesktopFromProp(Window w, char *prop1, char *prop2)
 {
     unsigned long *d;
@@ -295,7 +274,7 @@ static unsigned long ewmh_getDesktopFromProp(Window w, char *prop1, char *prop2)
 //
 // get current desktop in EWMH WM
 //
-unsigned long ewmh_getCurrentDesktop()
+static unsigned long ewmh_getCurrentDesktop()
 {
     return ewmh_getDesktopFromProp(root, "_NET_CURRENT_DESKTOP", "_WIN_WORKSPACE");
 }
@@ -303,7 +282,7 @@ unsigned long ewmh_getCurrentDesktop()
 //
 // get desktop of window w in EWMH WM
 //
-unsigned long ewmh_getDesktopOfWindow(Window w)
+static unsigned long ewmh_getDesktopOfWindow(Window w)
 {
     return ewmh_getDesktopFromProp(w, "_NET_WM_DESKTOP", "_WIN_WORKSPACE");
 }
@@ -311,7 +290,7 @@ unsigned long ewmh_getDesktopOfWindow(Window w)
 //
 // does window have _NET_WM_STATE_SKIP_TASKBAR
 //
-bool ewmh_skipWindowInTaskbar(Window w)
+static bool ewmh_skipWindowInTaskbar(Window w)
 {
     Atom *state;
     long unsigned int state_propsize;
@@ -338,3 +317,88 @@ bool ewmh_skipWindowInTaskbar(Window w)
     free(state);
     return ret;
 }
+
+static bool ewmhProbe(void)
+{
+    return ewmh_detectFeatures(&g.ewmh);
+}
+
+static int ewmhStartup(void)
+{
+    long rootevmask = 0;
+
+    // root: watching for _NET_ACTIVE_WINDOW
+    g.naw = XInternAtom(dpy, "_NET_ACTIVE_WINDOW", true);
+    rootevmask |= PropertyChangeMask;
+
+    // warning: this overwrites any previous value.
+    // note: x_setCommonPropertiesForAnyWindow does the similar thing
+    // for any window other than root and uiwin
+    XSelectInput(dpy, root, rootevmask);
+
+    return 1;
+}
+
+static int ewmhSetFocus(int winNdx)
+{
+    int r;
+    XWindowAttributes att;
+
+    r = ewmh_setFocus(winNdx, 0);
+    // XSetInputFocus stuff.
+    // skippy-xd does it and notes that "order is important".
+    // fixes #28.
+    // it must be protected by testing IsViewable in the same way
+    // as in x.c, or BadMatch happens after switching desktops.
+    XGetWindowAttributes(dpy, g.winlist[winNdx].id, &att);
+    if (att.map_state == IsViewable)
+        XSetInputFocus(dpy, g.winlist[winNdx].id, RevertToParent,
+                       CurrentTime);
+    return r;
+}
+
+static bool ewmhSkipFocusChangeEvent(void)
+{
+    return true;
+}
+
+static long ewmhEventMask(Window w)
+{
+    msg(0, "using direct focus tracking for 0x%lx\n", w);
+    return FocusChangeMask;
+}
+
+// PUBLIC
+
+//
+// focus window in EWMH WM
+// fwin used if non-zero, winNdx otherwise
+//
+int ewmh_setFocus(int winNdx, Window fwin)
+{
+    Window win = (fwin != 0) ? fwin : g.winlist[winNdx].id;
+    msg(1, "ewmh_setFocus win 0x%lx\n", win);
+    if (fwin == 0 && g.option_desktop != DESK_CURRENT) {
+        unsigned long wdesk = g.winlist[winNdx].desktop;
+        unsigned long cdesk = ewmh_getCurrentDesktop();
+        msg(1, "ewmh_setFocus fwin 0x%lx opt %d wdesk %lu cdesk %lu\n",
+            fwin, g.option_desktop, wdesk, cdesk);
+        if (cdesk != wdesk && wdesk != DESKTOP_UNKNOWN) {
+            ewmh_switch_desktop(wdesk);
+        }
+    }
+    ewmh_switch_window(win);
+    XMapRaised(dpy, win);
+    return 1;
+}
+
+struct WmOps WmEwmhOps = {
+    .probe = ewmhProbe,
+    .startup = ewmhStartup,
+    .winlist = ewmh_initWinlist,
+    .setFocus = ewmhSetFocus,
+    .getActiveWindow = ewmh_getActiveWindow,
+    .skipWindowInTaskbar = ewmh_skipWindowInTaskbar,
+    .skipFocusChangeEvent = ewmhSkipFocusChangeEvent,
+    .eventMask = ewmhEventMask,
+};
diff --git a/src/rp.c b/src/rp.c
index 1a0cfa9..f7ebc52 100644
--- a/src/rp.c
+++ b/src/rp.c
@@ -30,6 +30,8 @@ along with alttab.  If not, see <http://www.gnu.org/licenses/>.
 #include "alttab.h"
 #include "util.h"
 extern Globals g;
+extern Display *dpy;
+extern Window root;
 
 // PRIVATE
 
@@ -99,12 +101,10 @@ static int rp_add_windows_in_group(int current_group, int window_group)
     return 1;
 }
 
-// PUBLIC
-
 //
 // early initialization in ratpoison
 //
-int rp_startupWintasks()
+static int rp_startupWintasks()
 {
 
 // search for ratpoison executable for later execv
@@ -158,7 +158,7 @@ int rp_startupWintasks()
 //
 // initialize winlist/update sortlist from ratpoison output
 //
-int rp_initWinlist()
+static int rp_initWinlist()
 {
 #define  fallback    { msg(-1, "using current rp group\n") ; \
     return rp_add_windows_in_group(DESKTOP_UNKNOWN, DESKTOP_UNKNOWN); }
@@ -217,7 +217,7 @@ int rp_initWinlist()
 //
 // focus window in ratpoison
 //
-int rp_setFocus(int winNdx)
+static int rp_setFocus(int winNdx)
 {
     char selarg[64];
     char *args[] = { "ratpoison", "-c", selarg, NULL };
@@ -236,3 +236,49 @@ int rp_setFocus(int winNdx)
 
     return 1;
 }
+
+static bool ratpoisonProbe(void)
+{
+    unsigned long remain, len;
+    Atom nwm_prop, atype;
+    int form;
+    unsigned char *nwm;
+    bool ret = false;
+
+    nwm_prop = XInternAtom(dpy, "_NET_WM_NAME", false);
+    if (!XGetWindowProperty(dpy, root, nwm_prop, 0, MAXNAMESZ, false,
+                           AnyPropertyType, &atype, &form, &len, &remain,
+                            &nwm) == Success && nwm)
+        return false;
+
+    msg(0, "_NET_WM_NAME root property present: %s\n", nwm);
+    if (strstr((char *)nwm, "ratpoison") != NULL)
+        ret = true;
+
+    XFree(nwm);
+    return ret;
+}
+
+static int ratpoisonStartup(void)
+{
+    return rp_startupWintasks();
+}
+
+static int ratpoisonWinlist(void)
+{
+    return rp_initWinlist();
+}
+
+static int ratpoisonSetFocus(int idx)
+{
+    return rp_setFocus(idx);
+}
+
+// PUBLIC
+
+struct WmOps WmRatpoisonOps = {
+    .probe = ratpoisonProbe,
+    .startup = ratpoisonStartup,
+    .winlist = ratpoisonWinlist,
+    .setFocus = ratpoisonSetFocus,
+};
diff --git a/src/win.c b/src/win.c
index 8f35bfa..4afb92c 100644
--- a/src/win.c
+++ b/src/win.c
@@ -38,6 +38,69 @@ extern Window root;
 
 // PRIVATE
 
+static struct WmOps *WmOpsVariants[] = {
+    [WM_NO] = &WmNoOps,
+    [WM_EWMH] = &WmEwmhOps,
+    [WM_RATPOISON] = &WmRatpoisonOps,
+    [WM_TWM] = &WmTwmOps,
+};
+
+static struct WmOps *WmOps;
+
+static inline bool wmProbe(int wm)
+{
+    return (WmOpsVariants[wm]->probe != NULL) && (WmOpsVariants[wm]->probe());
+}
+
+static inline int wmStartup(void)
+{
+    if (WmOps->startup == NULL)
+        return 1;
+    return WmOps->startup();
+}
+
+static inline int wmInitWinlist(void)
+{
+    if (WmOps->winlist == NULL)
+        return 0;
+    return WmOps->winlist();
+}
+
+static inline int wmSetFocus(int idx)
+{
+    if (WmOps->setFocus == NULL)
+        return 0;
+    return WmOps->setFocus(idx);
+}
+
+static inline Window wmGetActiveWindow(void)
+{
+    if (WmOps->getActiveWindow == NULL)
+        return 0;
+    return WmOps->getActiveWindow();
+}
+
+static inline bool wmSkipWindowInTaskbar(Window w)
+{
+    if (WmOps->skipWindowInTaskbar == NULL)
+        return false;
+    return WmOps->skipWindowInTaskbar(w);
+}
+
+static inline bool wmSkipFocusChangeEvent(void)
+{
+    if (WmOps->skipFocusChangeEvent == NULL)
+        return false;
+    return WmOps->skipFocusChangeEvent();
+}
+
+static inline long wmEventMask(Window w)
+{
+    if (WmOps->eventMask == NULL)
+        return 0;
+    return WmOps->eventMask(w);
+}
+
 //
 // helper for windows' qsort
 // CAUSES O(log(N)) OR EVEN WORSE! reintroduce winlist[]->order instead?
@@ -99,6 +162,26 @@ static void print_winlist()
     }
 }
 
+//
+// this is where alttab is supposed to set properties or
+// register interest in event for ANY foreign window encountered.
+// warning: this is called only on addition to sortlist.
+//
+static void winSetCommonPropertiesForAnyWindow(Window win)
+{
+    long evmask = 0;
+    // root and our window are treated elsewhere
+    if (win == root || win == getUiwin())
+        return;
+    // for delete notification
+    evmask |= StructureNotifyMask;
+    // for focusIn notification
+    evmask |= wmEventMask(win);
+    // warning: this overwrites previous value
+    if (evmask != 0)
+        XSelectInput(dpy, win, evmask);
+}
+
 // PUBLIC
 
 //
@@ -135,47 +218,53 @@ void addToSortlist(Window w, bool to_head, bool move)
     if (add && !was) {
         // new window
         // register interest in events
-        x_setCommonPropertiesForAnyWindow(w);
+        winSetCommonPropertiesForAnyWindow(w);
     }
 }
 
+//
+// wmindex is the already validated option
+void initWin(int wmindex)
+{
+    int wm;
+
+    if (wmindex != WM_GUESS) {
+        wm = wmindex;
+        goto out;
+    }
+
+    if (wmProbe(WM_EWMH)) {
+        msg(0, "EWMH-compatible WM detected: %s\n", g.ewmh.wmname);
+        wm = WM_EWMH;
+        goto out;
+    }
+
+    if (wmProbe(WM_RATPOISON)) {
+        wm = WM_RATPOISON;
+        goto out;
+    }
+
+    msg(0, "unknown WM, using WM_TWM\n");
+    wm = WM_TWM;
+
+out:
+    msg(0, "WM: %d\n", wm);
+    WmOps = WmOpsVariants[wm];
+}
+
 //
 // early initialization
 // once per execution
 //
 int startupWintasks()
 {
-    long rootevmask = 0;
-
     g.sortlist = NULL;          // utlist head must be initialized to NULL
     g.ic = NULL;                // uthash too
     if (g.option_iconSrc != ISRC_RAM) {
         initIconHash(&(g.ic));
     }
-    // root: watching for _NET_ACTIVE_WINDOW
-    if (g.option_wm == WM_EWMH) {
-        g.naw = XInternAtom(dpy, "_NET_ACTIVE_WINDOW", true);
-        rootevmask |= PropertyChangeMask;
-    }
-    // warning: this overwrites any previous value.
-    // note: x_setCommonPropertiesForAnyWindow does the similar thing
-    // for any window other than root and uiwin
-    if (rootevmask != 0) {
-        XSelectInput(dpy, root, rootevmask);
-    }
 
-    switch (g.option_wm) {
-    case WM_NO:
-        return 1;
-    case WM_RATPOISON:
-        return rp_startupWintasks();
-    case WM_EWMH:
-        return 1;
-    case WM_TWM:
-        return 1;
-    default:
-        return 0;
-    }
+    return wmStartup();
 }
 
 //
@@ -508,23 +597,8 @@ int initWinlist(void)
         msg(1, "before initWinlist\n");
         print_sortlist();
     }
-    switch (g.option_wm) {
-    case WM_NO:
-        r = x_initWindowsInfoRecursive(root, 0);    // note: direction/current window index aren't used
-        break;
-    case WM_RATPOISON:
-        r = rp_initWinlist();
-        break;
-    case WM_EWMH:
-        r = ewmh_initWinlist();
-        break;
-    case WM_TWM:
-        r = x_initWindowsInfoRecursive(root, 0);
-        break;
-    default:
-        r = 0;
-        break;
-    }
+
+    r = wmInitWinlist();
 
     if (!r)
         __initWinlist();
@@ -571,34 +645,8 @@ void freeWinlist()
 int setFocus(int winNdx)
 {
     int r;
-    switch (g.option_wm) {
-    case WM_NO:
-        r = ewmh_setFocus(winNdx, 0);   // for WM which isn't identified as EWMH compatible but accepts setting focus (dwm)
-        x_setFocus(winNdx);
-        break;
-    case WM_RATPOISON:
-        r = rp_setFocus(winNdx);
-        break;
-    case WM_EWMH:
-        r = ewmh_setFocus(winNdx, 0);
-        // XSetInputFocus stuff.
-        // skippy-xd does it and notes that "order is important".
-        // fixes #28.
-        // it must be protected by testing IsViewable in the same way
-        // as in x.c, or BadMatch happens after switching desktops.
-        XWindowAttributes att;
-        XGetWindowAttributes(dpy, g.winlist[winNdx].id, &att);
-        if (att.map_state == IsViewable)
-            XSetInputFocus(dpy, g.winlist[winNdx].id, RevertToParent,
-                           CurrentTime);
-        break;
-    case WM_TWM:
-        r = ewmh_setFocus(winNdx, 0);
-        x_setFocus(winNdx);
-        break;
-    default:
-        return 0;
-    }
+
+    r = wmSetFocus(winNdx);
     // pull to head
     addToSortlist(g.winlist[winNdx].id, true, true);
     return r;
@@ -625,7 +673,7 @@ void winPropChangeEvent(XPropertyEvent e)
     if (e.atom != g.naw)
         return;
     // don't check for wm==EWMH, because _NET_ACTIVE_WINDOW changed for sure
-    aw = ewmh_getActiveWindow();
+    aw = wmGetActiveWindow();
     // can't get active window
     if (!aw)
         return;
@@ -636,7 +684,7 @@ void winPropChangeEvent(XPropertyEvent e)
     if (g.sortlist != NULL && aw == g.sortlist->id)
         return;
     // is window hidden in WM?
-    if (ewmh_skipWindowInTaskbar(aw))
+    if (wmSkipWindowInTaskbar(aw))
         return;
 /*
     // the i3 sortlist bug is not here, see ewmh.c init_winlist instead
@@ -745,7 +793,7 @@ void winFocusChangeEvent(XFocusChangeEvent e)
     // in non-EWMH only
     // probably should also maintain _NET_ACTIVE_WINDOW
     // support flag in EwmhFeatures
-    if (g.option_wm == WM_EWMH)
+    if (wmSkipFocusChangeEvent())
         return;
     // focusIn only
     if (e.type != FocusIn)
diff --git a/src/x.c b/src/x.c
index e59c6e6..6e0fe66 100644
--- a/src/x.c
+++ b/src/x.c
@@ -33,6 +33,13 @@ extern Window root;
 
 // PRIVATE
 
+// max recursion for searching windows
+// -1 is "everything"
+// in raw X this returns too much windows, "1" is probably sufficient
+// no need for an option
+static int max_reclevel;
+static int wm;
+
 //
 // get window group leader
 // to be used later. rewritten, not tested.
@@ -57,13 +64,11 @@ Window x_get_leader(Window win)
     return leader;
 }
 
-// PUBLIC
-
 //
 // set winlist,maxNdx recursively using raw Xlib
 // first call should be (win=root, reclevel=0)
 //
-int x_initWindowsInfoRecursive(Window win, int reclevel)
+static int x_initWindowsInfoRecursive(Window win, int reclevel)
 {
 
     Window root, parent;
@@ -88,24 +93,24 @@ int x_initWindowsInfoRecursive(Window win, int reclevel)
 // caveat: in rp, skips anything except of visible window
 // probably add an option for this in WMs too?
     wa.map_state = 0;
-    if (g.option_wm != WM_TWM)
+    if (wm != WM_TWM)
         XGetWindowAttributes(dpy, win, &wa);
 
 // in twm-like, add only windows with a name
     winname = NULL;
-    if (g.option_wm == WM_TWM) {
+    if (wm == WM_TWM) {
         winname = get_x_property(win, XA_STRING, "WM_NAME", NULL);
     }
 // insert detailed window data in window list
-    if ((g.option_wm == WM_TWM || wa.map_state == IsViewable)
-        && reclevel != 0 && (g.option_wm != WM_TWM || winname != NULL)
-//            && (g.option_wm != WM_TWM || leader == win)
+    if ((wm == WM_TWM || wa.map_state == IsViewable)
+        && reclevel != 0 && (wm != WM_TWM || winname != NULL)
+//            && (wm != WM_TWM || leader == win)
         && !common_skipWindow(win, DESKTOP_UNKNOWN, DESKTOP_UNKNOWN)
         ) {
         addWindowInfo(win, reclevel, 0, DESKTOP_UNKNOWN, winname);
     }
 // skip children if max recursion level reached
-    if (g.option_max_reclevel != -1 && reclevel >= g.option_max_reclevel)
+    if (max_reclevel != -1 && reclevel >= max_reclevel)
         return 1;
 
 // recursion
@@ -126,7 +131,7 @@ int x_initWindowsInfoRecursive(Window win, int reclevel)
 //
 // set window focus in raw X
 //
-int x_setFocus(int wndx)
+static int x_setFocus(int wndx)
 {
     Window w = g.winlist[wndx].id;
 
@@ -149,25 +154,47 @@ int x_setFocus(int wndx)
     return 1;
 }
 
-//
-// this is where alttab is supposed to set properties or
-// register interest in event for ANY foreign window encountered.
-// warning: this is called only on addition to sortlist.
-//
-void x_setCommonPropertiesForAnyWindow(Window win)
+static int xSetFocus(int idx)
 {
-    long evmask = 0;
-    // root and our window are treated elsewhere
-    if (win == root || win == getUiwin())
-        return;
-    // for delete notification
-    evmask |= StructureNotifyMask;
-    // for focusIn notification
-    if (g.option_wm != WM_EWMH) {
-        msg(0, "using direct focus tracking for 0x%lx\n", win);
-        evmask |= FocusChangeMask;
-    }
-    // warning: this overwrites previous value
-    if (evmask != 0)
-        XSelectInput(dpy, win, evmask);
+    int r;
+
+    // for WM which isn't identified as EWMH compatible
+    // but accepts setting focus (dwm)
+    r = ewmh_setFocus(idx, 0);
+    x_setFocus(idx);
+
+    return r;
 }
+
+static int xStartup(void)
+{
+    wm = WM_NO;
+    max_reclevel = 1;
+    return 1;
+}
+
+static int twmStartup(void)
+{
+    wm = WM_TWM;
+    max_reclevel = -1;
+    return 1;
+}
+
+static int xWinlist(void)
+{
+    return x_initWindowsInfoRecursive(root, 0);
+}
+
+// PUBLIC
+
+struct WmOps WmNoOps = {
+    .startup = xStartup,
+    .winlist = xWinlist,
+    .setFocus = xSetFocus,
+};
+
+struct WmOps WmTwmOps = {
+    .startup = twmStartup,
+    .winlist = xWinlist,
+    .setFocus = xSetFocus,
+};