diff --git a/config.def.h b/config.def.h
index 353aa83..e705841 100644
--- a/config.def.h
+++ b/config.def.h
@@ -3,6 +3,8 @@
 /* appearance */
 static const unsigned int borderpx  = 1;        /* border pixel of windows */
 static const unsigned int snap      = 32;       /* snap pixel */
+static const int swallowfloating    = 0;        /* 1 means swallow floating windows by default */
+static const int swterminheritfs    = 1;        /* 1 terminal inherits fullscreen on unswallow, 0 otherwise */
 static const unsigned int gappih    = 15;       /* horiz inner gap between windows */
 static const unsigned int gappiv    = 15;       /* vert inner gap between windows */
 static const unsigned int gappoh    = 10;       /* horiz outer gap between windows and screen edge */
@@ -33,9 +35,11 @@ static const Rule rules[] = {
 	 *	WM_CLASS(STRING) = instance, class
 	 *	WM_NAME(STRING) = title
 	 */
-	/* class      instance    title       tags mask     isfloating   monitor */
-	{ "Gimp",     NULL,       NULL,       0,            1,           -1 },
-	{ "Firefox",  NULL,       NULL,       1 << 8,       0,           -1 },
+	/* class      instance    title            tags mask  isfloating  isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,            0,         1,          0,           0,        -1 },
+	{ "Firefox",  NULL,       NULL,            1 << 8,    0,          0,          -1,        -1 },
+	{ "St",       NULL,       NULL,            0,         0,          1,           0,        -1 },
+	{ NULL,       NULL,       "Event Tester",  0,         0,          0,           1,        -1 }, /* xev */
 };
 
 /* layout(s) */
diff --git a/config.h b/config.h
index 353aa83..e705841 100644
--- a/config.h
+++ b/config.h
@@ -3,6 +3,8 @@
 /* appearance */
 static const unsigned int borderpx  = 1;        /* border pixel of windows */
 static const unsigned int snap      = 32;       /* snap pixel */
+static const int swallowfloating    = 0;        /* 1 means swallow floating windows by default */
+static const int swterminheritfs    = 1;        /* 1 terminal inherits fullscreen on unswallow, 0 otherwise */
 static const unsigned int gappih    = 15;       /* horiz inner gap between windows */
 static const unsigned int gappiv    = 15;       /* vert inner gap between windows */
 static const unsigned int gappoh    = 10;       /* horiz outer gap between windows and screen edge */
@@ -33,9 +35,11 @@ static const Rule rules[] = {
 	 *	WM_CLASS(STRING) = instance, class
 	 *	WM_NAME(STRING) = title
 	 */
-	/* class      instance    title       tags mask     isfloating   monitor */
-	{ "Gimp",     NULL,       NULL,       0,            1,           -1 },
-	{ "Firefox",  NULL,       NULL,       1 << 8,       0,           -1 },
+	/* class      instance    title            tags mask  isfloating  isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,            0,         1,          0,           0,        -1 },
+	{ "Firefox",  NULL,       NULL,            1 << 8,    0,          0,          -1,        -1 },
+	{ "St",       NULL,       NULL,            0,         0,          1,           0,        -1 },
+	{ NULL,       NULL,       "Event Tester",  0,         0,          0,           1,        -1 }, /* xev */
 };
 
 /* layout(s) */
diff --git a/config.mk b/config.mk
index 8efca9a..fc05587 100644
--- a/config.mk
+++ b/config.mk
@@ -20,10 +20,14 @@ FREETYPEINC = /usr/include/freetype2
 # OpenBSD (uncomment)
 #FREETYPEINC = ${X11INC}/freetype2
 #MANPREFIX = ${PREFIX}/man
+#KVMLIB = -lkvm
+
+# This is needed for the swallow patch
+XCBLIBS = -lX11-xcb -lxcb -lxcb-res
 
 # includes and libs
 INCS = -I${X11INC} -I${FREETYPEINC}
-LIBS = -L${X11LIB} -lX11 ${XINERAMALIBS} ${FREETYPELIBS}
+LIBS = -L${X11LIB} -lX11 ${XINERAMALIBS} ${FREETYPELIBS} ${XCBLIBS} ${KVMLIB}
 
 # flags
 CPPFLAGS = -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_XOPEN_SOURCE=700L -DVERSION=\"${VERSION}\" ${XINERAMAFLAGS}
diff --git a/dwm.c b/dwm.c
index aefba52..dc48459 100644
--- a/dwm.c
+++ b/dwm.c
@@ -40,6 +40,12 @@
 #include <X11/extensions/Xinerama.h>
 #endif /* XINERAMA */
 #include <X11/Xft/Xft.h>
+#include <X11/Xlib-xcb.h>
+#include <xcb/res.h>
+#ifdef __OpenBSD__
+#include <sys/sysctl.h>
+#include <kvm.h>
+#endif /* __OpenBSD */
 
 #include "drw.h"
 #include "util.h"
@@ -92,9 +98,12 @@ struct Client {
 	int basew, baseh, incw, inch, maxw, maxh, minw, minh, hintsvalid;
 	int bw, oldbw;
 	unsigned int tags;
-	int isfixed, isfloating, isurgent, neverfocus, oldstate, isfullscreen;
+	int isfixed, isfloating, isurgent, neverfocus, oldstate, isfullscreen, isterminal, noswallow;
+	int ignorecfgreqpos, ignorecfgreqsize;
+	pid_t pid;
 	Client *next;
 	Client *snext;
+	Client *swallowing;
 	Monitor *mon;
 	Window win;
 };
@@ -144,6 +153,8 @@ typedef struct {
 	const char *title;
 	unsigned int tags;
 	int isfloating;
+	int isterminal;
+	int noswallow;
 	int monitor;
 } Rule;
 
@@ -196,6 +207,7 @@ static void pop(Client *c);
 static void propertynotify(XEvent *e);
 static void quit(const Arg *arg);
 static Monitor *recttomon(int x, int y, int w, int h);
+static void replaceclient(Client *old, Client *new);
 static void resize(Client *c, int x, int y, int w, int h, int interact);
 static void resizeclient(Client *c, int x, int y, int w, int h);
 static void resizemouse(const Arg *arg);
@@ -240,6 +252,14 @@ static int xerrordummy(Display *dpy, XErrorEvent *ee);
 static int xerrorstart(Display *dpy, XErrorEvent *ee);
 static void zoom(const Arg *arg);
 
+static int swallow(Client *p, Client *c);
+static void unswallow(Client *c);
+static pid_t getparentprocess(pid_t p);
+static int isdescprocess(pid_t p, pid_t c);
+static Client *swallowingclient(Window w);
+static Client *termforwin(const Client *c);
+static pid_t winpid(Window w);
+
 /* variables */
 static const char broken[] = "broken";
 static char stext[256];
@@ -275,6 +295,7 @@ static Display *dpy;
 static Drw *drw;
 static Monitor *mons, *selmon;
 static Window root, wmcheckwin;
+static xcb_connection_t *xcon;
 
 /* configuration, allows nested code to access above variables */
 #include "config.h"
@@ -317,6 +338,8 @@ applyrules(Client *c)
 		&& (!r->class || strstr(class, r->class))
 		&& (!r->instance || strstr(instance, r->instance)))
 		{
+			c->isterminal = r->isterminal;
+			c->noswallow  = r->noswallow;
 			c->isfloating = r->isfloating;
 			c->tags |= r->tags;
 			for (m = mons; m && m->num != r->monitor; m = m->next);
@@ -611,22 +634,29 @@ configurerequest(XEvent *e)
 		if (ev->value_mask & CWBorderWidth)
 			c->bw = ev->border_width;
 		else if (c->isfloating || !selmon->lt[selmon->sellt]->arrange) {
+			if (c->ignorecfgreqpos && c->ignorecfgreqsize)
+				return;
+
 			m = c->mon;
-			if (ev->value_mask & CWX) {
-				c->oldx = c->x;
-				c->x = m->mx + ev->x;
+			if (!c->ignorecfgreqpos) {
+				if (ev->value_mask & CWX) {
+					c->oldx = c->x;
+					c->x = m->mx + ev->x;
+				}
+				if (ev->value_mask & CWY) {
+					c->oldy = c->y;
+					c->y = m->my + ev->y;
+				}
 			}
-			if (ev->value_mask & CWY) {
-				c->oldy = c->y;
-				c->y = m->my + ev->y;
-			}
-			if (ev->value_mask & CWWidth) {
-				c->oldw = c->w;
-				c->w = ev->width;
-			}
-			if (ev->value_mask & CWHeight) {
-				c->oldh = c->h;
-				c->h = ev->height;
+			if (!c->ignorecfgreqsize) {
+				if (ev->value_mask & CWWidth) {
+					c->oldw = c->w;
+					c->w = ev->width;
+				}
+				if (ev->value_mask & CWHeight) {
+					c->oldh = c->h;
+					c->h = ev->height;
+				}
 			}
 			if ((c->x + c->w) > m->mx + m->mw && c->isfloating)
 				c->x = m->mx + (m->mw / 2 - WIDTH(c) / 2); /* center in x direction */
@@ -703,6 +733,8 @@ destroynotify(XEvent *e)
 
 	if ((c = wintoclient(ev->window)))
 		unmanage(c, 1);
+	else if ((c = swallowingclient(ev->window)))
+		unmanage(c->swallowing, 1);
 }
 
 void
@@ -1145,12 +1177,14 @@ killclient(const Arg *arg)
 void
 manage(Window w, XWindowAttributes *wa)
 {
-	Client *c, *t = NULL;
+	Client *c, *t = NULL, *term = NULL;
 	Window trans = None;
 	XWindowChanges wc;
+	int focusclient = 1;
 
 	c = ecalloc(1, sizeof(Client));
 	c->win = w;
+	c->pid = winpid(w);
 	/* geometry */
 	c->x = c->oldx = wa->x;
 	c->y = c->oldy = wa->y;
@@ -1165,6 +1199,7 @@ manage(Window w, XWindowAttributes *wa)
 	} else {
 		c->mon = selmon;
 		applyrules(c);
+		term = termforwin(c);
 	}
 
 	if (c->x + WIDTH(c) > c->mon->wx + c->mon->ww)
@@ -1188,18 +1223,35 @@ manage(Window w, XWindowAttributes *wa)
 		c->isfloating = c->oldstate = trans != None || c->isfixed;
 	if (c->isfloating)
 		XRaiseWindow(dpy, c->win);
-	attach(c);
-	attachstack(c);
+
+	/* Do not attach client if it is being swallowed */
+	if (term && swallow(term, c)) {
+		/* Do not let swallowed client steal focus unless the terminal has focus */
+		focusclient = (term == selmon->sel);
+	} else {
+		attach(c);
+
+		if (focusclient || !c->mon->sel || !c->mon->stack)
+			attachstack(c);
+		else {
+			c->snext = c->mon->sel->snext;
+			c->mon->sel->snext = c;
+		}
+	}
+
 	XChangeProperty(dpy, root, netatom[NetClientList], XA_WINDOW, 32, PropModeAppend,
 		(unsigned char *) &(c->win), 1);
 	XMoveResizeWindow(dpy, c->win, c->x + 2 * sw, c->y, c->w, c->h); /* some windows require this */
 	setclientstate(c, NormalState);
-	if (c->mon == selmon)
-		unfocus(selmon->sel, 0);
-	c->mon->sel = c;
+	if (focusclient) {
+		if (c->mon == selmon)
+			unfocus(selmon->sel, 0);
+		c->mon->sel = c;
+	}
 	arrange(c->mon);
 	XMapWindow(dpy, c->win);
-	focus(NULL);
+	if (focusclient)
+		focus(NULL);
 }
 
 void
@@ -1389,6 +1441,82 @@ recttomon(int x, int y, int w, int h)
 	return r;
 }
 
+void
+replaceclient(Client *old, Client *new)
+{
+	Client *c = NULL;
+	Monitor *mon = old->mon;
+	int x, y, w, h, f, bw;
+
+	new->mon = mon;
+	new->tags = old->tags;
+
+	new->next = old->next;
+	new->snext = old->snext;
+
+	if (old == mon->clients) {
+		mon->clients = new;
+	} else {
+		for (c = mon->clients; c && c->next != old; c = c->next);
+		c->next = new;
+	}
+
+	if (old == mon->stack) {
+		mon->stack = new;
+	} else {
+		for (c = mon->stack; c && c->snext != old; c = c->snext);
+		c->snext = new;
+	}
+
+	old->next = NULL;
+	old->snext = NULL;
+
+	/* Capture the normal state of the old client */
+	if (old->isfullscreen) {
+		x = old->oldx;
+		y = old->oldy;
+		w = old->oldw;
+		h = old->oldh;
+		f = old->oldstate;
+		bw = old->oldbw;
+	} else {
+		x = old->x;
+		y = old->y;
+		w = old->w;
+		h = old->h;
+		f = old->isfloating;
+		bw = old->bw;
+	}
+
+	/* Work out whether the new client should gain fullscreen, lose fullscreen or remain as-is */
+	if (!new->isfullscreen && old->isfullscreen && (swterminheritfs || !new->isterminal)) {
+		/* Gain fullscreen */
+		setfullscreen(new, 1);
+	} else if (new->isfullscreen && !old->isfullscreen && !old->isterminal) {
+		/* Lose fullscreen */
+		setfullscreen(new, 0);
+	}
+
+	/* Correct state of new client based on the normal state of the old client */
+	if (new->isfullscreen) {
+		new->oldbw = bw;
+		new->oldstate = f;
+		new->oldx = x;
+		new->oldy = y;
+		new->oldw = w;
+		new->oldh = h;
+	} else {
+		new->bw = bw;
+		new->isfloating = f;
+
+		if (ISVISIBLE(new) && new->isfloating) {
+			resize(new, x, y, w, h, 0);
+		}
+	}
+
+	XMoveWindow(dpy, old->win, WIDTH(old) * -2, old->y);
+}
+
 void
 resize(Client *c, int x, int y, int w, int h, int interact)
 {
@@ -1795,6 +1923,28 @@ spawn(const Arg *arg)
 	}
 }
 
+int
+swallow(Client *t, Client *c)
+{
+	if (c->noswallow || c->isterminal)
+		return 0;
+	if (!swallowfloating && (c->isfullscreen ? c->oldstate : c->isfloating))
+		return 0;
+
+	replaceclient(t, c);
+	c->ignorecfgreqpos = 1;
+	c->swallowing = t;
+
+	return 1;
+}
+
+void
+unswallow(Client *c)
+{
+	replaceclient(c, c->swallowing);
+	c->swallowing = NULL;
+}
+
 void
 tag(const Arg *arg)
 {
@@ -1899,9 +2049,17 @@ unfocus(Client *c, int setfocus)
 void
 unmanage(Client *c, int destroyed)
 {
+	Client *s;
 	Monitor *m = c->mon;
 	XWindowChanges wc;
 
+	if (c->swallowing)
+		unswallow(c);
+
+	s = swallowingclient(c->win);
+	if (s)
+		s->swallowing = NULL;
+
 	detach(c);
 	detachstack(c);
 	if (!destroyed) {
@@ -2205,6 +2363,133 @@ view(const Arg *arg)
 	arrange(selmon);
 }
 
+pid_t
+winpid(Window w)
+{
+	pid_t result = 0;
+
+#ifdef __linux__
+	xcb_res_client_id_spec_t spec = {0};
+	spec.client = w;
+	spec.mask = XCB_RES_CLIENT_ID_MASK_LOCAL_CLIENT_PID;
+
+	xcb_generic_error_t *e = NULL;
+	xcb_res_query_client_ids_cookie_t c = xcb_res_query_client_ids(xcon, 1, &spec);
+	xcb_res_query_client_ids_reply_t *r = xcb_res_query_client_ids_reply(xcon, c, &e);
+
+	if (!r)
+		return (pid_t)0;
+
+	xcb_res_client_id_value_iterator_t i = xcb_res_query_client_ids_ids_iterator(r);
+	for (; i.rem; xcb_res_client_id_value_next(&i)) {
+		spec = i.data->spec;
+		if (spec.mask & XCB_RES_CLIENT_ID_MASK_LOCAL_CLIENT_PID) {
+			uint32_t *t = xcb_res_client_id_value_value(i.data);
+			result = *t;
+			break;
+		}
+	}
+
+	free(r);
+
+	if (result == (pid_t)-1)
+		result = 0;
+#endif /* __linux__ */
+#ifdef __OpenBSD__
+	Atom type;
+	int format;
+	unsigned long len, bytes;
+	unsigned char *prop;
+	pid_t ret;
+
+	if (XGetWindowProperty(dpy, w, XInternAtom(dpy, "_NET_WM_PID", 0), 0, 1, False, AnyPropertyType, &type, &format, &len, &bytes, &prop) != Success || !prop)
+		return 0;
+
+	ret = *(pid_t*)prop;
+	XFree(prop);
+	result = ret;
+#endif /* __OpenBSD__ */
+
+	return result;
+}
+
+pid_t
+getparentprocess(pid_t p)
+{
+	unsigned int v = 0;
+
+#ifdef __linux__
+	FILE *f;
+	char buf[256];
+	snprintf(buf, sizeof(buf) - 1, "/proc/%u/stat", (unsigned)p);
+
+	if (!(f = fopen(buf, "r")))
+		return 0;
+
+	fscanf(f, "%*u %*s %*c %u", &v);
+	fclose(f);
+#endif /* __linux__*/
+
+#ifdef __OpenBSD__
+	int n;
+	kvm_t *kd;
+	struct kinfo_proc *kp;
+
+	kd = kvm_openfiles(NULL, NULL, NULL, KVM_NO_FILES, NULL);
+	if (!kd)
+		return 0;
+
+	kp = kvm_getprocs(kd, KERN_PROC_PID, p, sizeof(*kp), &n);
+	v = kp->p_ppid;
+#endif /* __OpenBSD__ */
+
+	return (pid_t)v;
+}
+
+int
+isdescprocess(pid_t p, pid_t c)
+{
+	while (p != c && c != 0)
+		c = getparentprocess(c);
+
+	return (int)c;
+}
+
+Client *
+termforwin(const Client *w)
+{
+	Client *c;
+	Monitor *m;
+
+	if (!w->pid || w->isterminal)
+		return NULL;
+
+	for (m = mons; m; m = m->next) {
+		for (c = m->clients; c; c = c->next) {
+			if (c->isterminal && !c->swallowing && c->pid && isdescprocess(c->pid, w->pid))
+				return c;
+		}
+	}
+
+	return NULL;
+}
+
+Client *
+swallowingclient(Window w)
+{
+	Client *c;
+	Monitor *m;
+
+	for (m = mons; m; m = m->next) {
+		for (c = m->clients; c; c = c->next) {
+			if (c->swallowing && c->swallowing->win == w)
+				return c;
+		}
+	}
+
+	return NULL;
+}
+
 Client *
 wintoclient(Window w)
 {
@@ -2294,10 +2579,12 @@ main(int argc, char *argv[])
 		fputs("warning: no locale support\n", stderr);
 	if (!(dpy = XOpenDisplay(NULL)))
 		die("dwm: cannot open display");
+	if (!(xcon = XGetXCBConnection(dpy)))
+		die("dwm: cannot get xcb connection\n");
 	checkotherwm();
 	setup();
 #ifdef __OpenBSD__
-	if (pledge("stdio rpath proc exec", NULL) == -1)
+	if (pledge("stdio rpath proc exec ps", NULL) == -1)
 		die("pledge");
 #endif /* __OpenBSD__ */
 	scan();