diff -Naur dwm-6.1/config.def.h dwm-6.1-patched/config.def.h
--- dwm-6.1/config.def.h	2015-11-09 06:39:37.000000000 +0800
+++ dwm-6.1-patched/config.def.h	2016-02-17 16:46:11.137603047 +0800
@@ -11,6 +11,8 @@
 static const char selbordercolor[]  = "#005577";
 static const char selbgcolor[]      = "#005577";
 static const char selfgcolor[]      = "#eeeeee";
+static const char normmarkcolor[]   = "#775500";
+static const char selmarkcolor[]    = "#775577";
 static const unsigned int borderpx  = 1;        /* border pixel of windows */
 static const unsigned int snap      = 32;       /* snap pixel */
 static const int showbar            = 1;        /* 0 means no bar */
@@ -68,7 +70,6 @@
 	{ MODKEY,                       XK_d,      incnmaster,     {.i = -1 } },
 	{ MODKEY,                       XK_h,      setmfact,       {.f = -0.05} },
 	{ MODKEY,                       XK_l,      setmfact,       {.f = +0.05} },
-	{ MODKEY,                       XK_Return, zoom,           {0} },
 	{ MODKEY,                       XK_Tab,    view,           {0} },
 	{ MODKEY|ShiftMask,             XK_c,      killclient,     {0} },
 	{ MODKEY,                       XK_t,      setlayout,      {.v = &layouts[0]} },
@@ -82,6 +83,9 @@
 	{ MODKEY,                       XK_period, focusmon,       {.i = +1 } },
 	{ MODKEY|ShiftMask,             XK_comma,  tagmon,         {.i = -1 } },
 	{ MODKEY|ShiftMask,             XK_period, tagmon,         {.i = +1 } },
+	{ MODKEY,                       XK_Return, swapclient,     {0} },
+	{ MODKEY,                       XK_o,      swapfocus,      {0} },
+	{ MODKEY,                       XK_semicolon, togglemark,  {0} }, 
 	TAGKEYS(                        XK_1,                      0)
 	TAGKEYS(                        XK_2,                      1)
 	TAGKEYS(                        XK_3,                      2)
diff -Naur dwm-6.1/drw.h dwm-6.1-patched/drw.h
--- dwm-6.1/drw.h	2015-11-09 06:39:37.000000000 +0800
+++ dwm-6.1-patched/drw.h	2016-02-17 16:18:47.424219808 +0800
@@ -23,6 +23,7 @@
 	Clr *fg;
 	Clr *bg;
 	Clr *border;
+	Clr *mark;
 } ClrScheme;
 
 typedef struct {
diff -Naur dwm-6.1/dwm.c dwm-6.1-patched/dwm.c
--- dwm-6.1/dwm.c	2015-11-09 06:39:37.000000000 +0800
+++ dwm-6.1-patched/dwm.c	2016-02-17 16:41:55.737595294 +0800
@@ -201,16 +201,20 @@
 static void setfocus(Client *c);
 static void setfullscreen(Client *c, int fullscreen);
 static void setlayout(const Arg *arg);
+static void stemark(const Arg *arg);
 static void setmfact(const Arg *arg);
 static void setup(void);
 static void showhide(Client *c);
 static void sigchld(int unused);
 static void spawn(const Arg *arg);
+static void swapclient(const Arg *arg);
+static void swapfocus(const Arg *arg);
 static void tag(const Arg *arg);
 static void tagmon(const Arg *arg);
 static void tile(Monitor *);
 static void togglebar(const Arg *arg);
 static void togglefloating(const Arg *arg);
+static void togglemark(const Arg *arg);
 static void toggletag(const Arg *arg);
 static void toggleview(const Arg *arg);
 static void unfocus(Client *c, int setfocus);
@@ -266,6 +270,7 @@
 static Drw *drw;
 static Monitor *mons, *selmon;
 static Window root;
+static Client *mark;
 
 /* configuration, allows nested code to access above variables */
 #include "config.h"
@@ -482,6 +487,7 @@
 	for (i = 0; i < CurLast; i++)
 		drw_cur_free(drw, cursor[i]);
 	for (i = 0; i < SchemeLast; i++) {
+		drw_clr_free(scheme[i].mark);
 		drw_clr_free(scheme[i].border);
 		drw_clr_free(scheme[i].bg);
 		drw_clr_free(scheme[i].fg);
@@ -807,7 +813,12 @@
 		detachstack(c);
 		attachstack(c);
 		grabbuttons(c, 1);
-		XSetWindowBorder(dpy, c->win, scheme[SchemeSel].border->pix);
+		if (c == mark)
+			XSetWindowBorder(dpy, c->win,
+					scheme[SchemeSel].mark->pix);
+		else 
+			XSetWindowBorder(dpy, c->win,
+					scheme[SchemeSel].border->pix);
 		setfocus(c);
 	} else {
 		XSetInputFocus(dpy, root, RevertToPointerRoot, CurrentTime);
@@ -1018,6 +1029,8 @@
 {
 	if (!selmon->sel)
 		return;
+	if (mark == selmon->sel)
+		setmark(0);
 	if (!sendevent(selmon->sel, wmatom[WMDelete])) {
 		XGrabServer(dpy);
 		XSetErrorHandler(xerrordummy);
@@ -1065,7 +1078,10 @@
 
 	wc.border_width = c->bw;
 	XConfigureWindow(dpy, w, CWBorderWidth, &wc);
-	XSetWindowBorder(dpy, w, scheme[SchemeNorm].border->pix);
+	if (c == mark)
+		XSetWindowBorder(dpy, w, scheme[SchemeNorm].mark->pix);
+	else
+		XSetWindowBorder(dpy, w, scheme[SchemeNorm].border->pix);
 	configure(c); /* propagates border_width, if size doesn't change */
 	updatewindowtype(c);
 	updatesizehints(c);
@@ -1528,6 +1544,23 @@
 		drawbar(selmon);
 }
 
+void
+setmark(Client *c)
+{
+	if (c == mark)
+		return;
+	if (mark) {
+		XSetWindowBorder(dpy, mark->win, scheme[mark == selmon->sel
+				? SchemeSel : SchemeNorm].border->pix);
+		mark = 0;
+	}
+	if (c) {
+		XSetWindowBorder(dpy, c->win, scheme[c == selmon->sel 
+				? SchemeSel : SchemeNorm].mark->pix);
+		mark = c;
+	}
+}
+
 /* arg > 1.0 will set mfact absolutly */
 void
 setmfact(const Arg *arg)
@@ -1580,9 +1613,11 @@
 	cursor[CurResize] = drw_cur_create(drw, XC_sizing);
 	cursor[CurMove] = drw_cur_create(drw, XC_fleur);
 	/* init appearance */
+	scheme[SchemeNorm].mark = drw_clr_create(drw, normmarkcolor);
 	scheme[SchemeNorm].border = drw_clr_create(drw, normbordercolor);
 	scheme[SchemeNorm].bg = drw_clr_create(drw, normbgcolor);
 	scheme[SchemeNorm].fg = drw_clr_create(drw, normfgcolor);
+	scheme[SchemeSel].mark = drw_clr_create(drw, selmarkcolor);
 	scheme[SchemeSel].border = drw_clr_create(drw, selbordercolor);
 	scheme[SchemeSel].bg = drw_clr_create(drw, selbgcolor);
 	scheme[SchemeSel].fg = drw_clr_create(drw, selfgcolor);
@@ -1646,6 +1681,50 @@
 }
 
 void
+swapclient(const Arg *arg)
+{
+	Client *s, *m, t;
+
+	if (!mark) {
+		zoom(0);
+		return;
+	}
+	s = selmon->sel;
+	m = mark;
+	if (!s || m == s || !selmon->lt[selmon->sellt]->arrange)
+		return;
+	t = *s;
+	strcpy(s->name, m->name);
+	strcpy(m->name, t.name);
+	s->win = m->win;
+	m->win = t.win;
+	XMoveResizeWindow(dpy, s->win, s->x + 2 * sw, s->y, s->w, s->h);
+	arrange(s->mon);
+	XMapWindow(dpy, s->win);
+	XMoveResizeWindow(dpy, m->win, m->x + 2 * sw, m->y, m->w, m->h);
+	arrange(m->mon);
+	XMapWindow(dpy, m->win);
+
+	selmon->sel = m;
+	mark = s;
+	focus(s);
+	setmark(m);
+}
+
+void
+swapfocus(const Arg *arg)
+{
+	Client *t;
+
+	if (!selmon->sel || !mark || selmon->sel == mark) {
+		return;
+	}
+	t = mark;
+	setmark(selmon->sel);
+	focus(t);
+}
+
+void
 tag(const Arg *arg)
 {
 	if (selmon->sel && arg->ui & TAGMASK) {
@@ -1713,6 +1792,15 @@
 }
 
 void
+togglemark(const Arg *arg)
+{
+	if (!selmon->sel) {
+		return;
+	}
+	setmark(selmon->sel == mark ? 0 : selmon->sel);
+}
+
+void
 toggletag(const Arg *arg)
 {
 	unsigned int newtags;
@@ -1745,7 +1833,10 @@
 	if (!c)
 		return;
 	grabbuttons(c, 0);
-	XSetWindowBorder(dpy, c->win, scheme[SchemeNorm].border->pix);
+	if (c == mark)
+		XSetWindowBorder(dpy, c->win, scheme[SchemeNorm].mark->pix);
+	else
+		XSetWindowBorder(dpy, c->win, scheme[SchemeNorm].border->pix);
 	if (setfocus) {
 		XSetInputFocus(dpy, root, RevertToPointerRoot, CurrentTime);
 		XDeleteProperty(dpy, root, netatom[NetActiveWindow]);