Index: sys/boot/forth/menu.rc
===================================================================
--- sys/boot/forth/menu.rc
+++ sys/boot/forth/menu.rc
@@ -65,6 +65,11 @@
 set mainmenu_keycode[6]=111
 set mainansi_caption[6]="Configure Boot ^[1mO^[mptions..."
 
+set mainmenu_caption[7]="Select Boot [E]nvironment..."
+set mainmenu_command[7]="3 goto_menu"
+set mainmenu_keycode[7]=101
+set mainansi_caption[7]="Select Boot ^[1mE^[37mnvironment..."
+
 \ 
 \ BOOT OPTIONS MENU
 \ 
@@ -116,6 +121,53 @@
 set optionsansi_caption[6]="^[1mV^[merbose..... ^[34;1mOff^[m"
 set optionstoggled_ansi[6]="^[1mV^[merbose..... ^[32;7mOn^[m"
 
+\ 
+\ BOOT ENVIRONMENT MENU
+\ 
+
+set menuset_name3="bootenv"
+
+set bootenvmenu_caption[1]="Back to Main Menu [Backspace]"
+set bootenvmenu_command[1]="1 goto_menu"
+set bootenvmenu_keycode[1]=8
+set bootenvansi_caption[1]="Back to Main Menu ^[1m[Backspace]^[37m"
+
+set bootenvmenu_caption[2]="Choice: "
+set bootenvmenu_command[2]="true"
+set bootenvmenu_keycode[2]=27
+set bootenvansi_caption[2]="^[1m${bootenvmenu_caption[2]}^[37m"
+
+set bemenu_current="Choice: "
+set beansi_current="^[1m${bemenu_current}^[37m"
+: init_bootenv ( -- )
+	s" set menu_caption[2]=${bemenu_current}${vfs.root.mountfrom}" evaluate
+	s" set ansi_caption[2]=${beansi_current}${vfs.root.mountfrom}" evaluate
+;
+
+set bootenvmenu_init="init_bootenv"
+unset bootenvmenu_caption[2]
+unset bootenvansi_caption[2]
+
+: set_bootenv ( N -- N TRUE )
+	dup s" set vfs.root.mountfrom=${bootenv_root[E]}" 38 +c! evaluate
+	s" set currdev=${vfs.root.mountfrom}:" evaluate
+	s" /boot/defaults/loader.conf" read-conf
+	s" /boot/loader.conf" read-conf
+	s" unload" evaluate
+	init_bootenv
+	menu-refresh
+	TRUE
+;
+
+set bootenvmenu_caption[3]="[A]ctive: ${vfs.root.mountfrom}"
+set bootenvansi_caption[3]="^[1mA^[37mctive: ${vfs.root.mountfrom}"
+set bootenvmenu_keycode[3]=97
+set bootenvmenu_command[3]="set_bootenv"
+set bootenv_root[3]="${zfs_be_active}"
+
+set bootenvmenu_options=4
+set bootenvmenu_optionstext="Boot Environments:"
+
 \ Enable automatic booting (add ``autoboot_delay=N'' to loader.conf(5) to
 \ customize the timeout; default is 10-seconds)
 \ 
Index: sys/boot/forth/shortcuts.4th
===================================================================
--- sys/boot/forth/shortcuts.4th
+++ sys/boot/forth/shortcuts.4th
@@ -48,3 +48,16 @@
 	menu-init       \ Initialize menu and draw bounding box (in menu.4th)
 	menu-display    \ Launch interactive menu (in menu.4th)
 ;
+
+\ This "shortcut" word will fully redraw the current menu.
+\ The regular menu-redraw word does not clear the screen, and if there is
+\ any excess output, the menu will be redrawn incorrectly
+\ 
+: menu-refresh ( -- )
+	clear           \ Clear the screen (in screen.4th)
+	print_version   \ print version string (bottom-right; see version.4th)
+	draw-beastie    \ Draw FreeBSD logo at right (in beastie.4th)
+	draw-brand      \ Draw brand.4th logo at top (in brand.4th)
+	menu-init       \ Initialize menu and draw bounding box (in menu.4th)
+	menu-redraw     \ Redraw menu (in menu.4th)
+;
Index: sys/boot/i386/loader/main.c
===================================================================
--- sys/boot/i386/loader/main.c
+++ sys/boot/i386/loader/main.c
@@ -69,6 +69,7 @@
 static void		isa_outb(int port, int value);
 void			exit(int code);
 #ifdef LOADER_ZFS_SUPPORT
+static void		list_zfs_bootenv(char *currdev);
 static void		i386_zfs_probe(void);
 #endif
 
@@ -299,12 +300,41 @@
 	new_currdev.d_unit = 0;
     }
 
+#ifdef LOADER_ZFS_SUPPORT
+    list_zfs_bootenv(zfs_fmtdev(&new_currdev));
+#endif
+
     env_setenv("currdev", EV_VOLATILE, i386_fmtdev(&new_currdev),
 	       i386_setcurrdev, env_nounset);
     env_setenv("loaddev", EV_VOLATILE, i386_fmtdev(&new_currdev), env_noset,
 	       env_nounset);
 }
 
+#ifdef LOADER_ZFS_SUPPORT
+static void
+list_zfs_bootenv(char *currdev)
+{
+	char *beroot;
+
+	/* Remove the trailing : */
+	currdev[strlen(currdev) - 1] = '\0';
+	setenv("zfs_be_active", currdev, 1);
+	/* Do not overwrite if already set */
+	setenv("vfs.root.mountfrom", currdev, 0);
+	/* Forward past zfs: */
+	currdev = strchr(currdev, ':');
+	currdev++;
+	/* Remove the last element (current bootenv) */
+	beroot = strrchr(currdev, '/');
+	beroot[0] = '\0';
+
+	beroot = currdev;
+	
+	if (beroot && beroot[0] != '\0')
+		zfs_bootenv(beroot);
+}
+#endif
+
 COMMAND_SET(reboot, "reboot", "reboot the system", command_reboot);
 
 static int
@@ -360,6 +390,27 @@
     }
     return (CMD_OK);
 }
+
+COMMAND_SET(reloadbe, "reloadbe", "refresh the list of ZFS Boot Environments",
+    command_reloadbe);
+
+static int
+command_reloadbe(int argc, char *argv[])
+{
+    int err;
+
+    if (argc != 2) {
+	command_errmsg = "wrong number of arguments";
+	return (CMD_ERROR);
+    }
+
+    err = zfs_bootenv(argv[1]);
+    if (err != 0) {
+	command_errmsg = strerror(err);
+	return (CMD_ERROR);
+    }
+    return (CMD_OK);
+}
 #endif
 
 /* ISA bus access functions for PnP. */
Index: sys/boot/zfs/libzfs.h
===================================================================
--- sys/boot/zfs/libzfs.h
+++ sys/boot/zfs/libzfs.h
@@ -62,6 +62,8 @@
 char	*zfs_fmtdev(void *vdev);
 int	zfs_probe_dev(const char *devname, uint64_t *pool_guid);
 int	zfs_list(const char *name);
+int	zfs_bootenv(const char *name);
+int	zfs_set_env(const char *name);
 
 extern struct devsw zfs_dev;
 extern struct fs_ops zfs_fsops;
Index: sys/boot/zfs/zfs.c
===================================================================
--- sys/boot/zfs/zfs.c
+++ sys/boot/zfs/zfs.c
@@ -80,6 +80,8 @@
 	zap_leaf_phys_t	*f_zap_leaf;	/* zap leaf buffer */
 };
 
+static int	zfs_env_index = 0;
+
 /*
  * Open a file.
  */
@@ -694,3 +696,93 @@
 	rv = zfs_list_dataset(spa, objid);
 	return (rv);
 }
+
+int
+zfs_bootenv(const char *name)
+{
+	static char	poolname[ZFS_MAXNAMELEN];
+	uint64_t	objid;
+	spa_t		*spa;
+	const char	*dsname;
+	char		*index_str;
+	int		len;
+	int		rv;
+
+	setenv("zfs_beroot", name, 1);
+
+	zfs_env_index = 4;
+	len = strlen(name);
+	dsname = strchr(name, '/');
+	if (dsname != NULL) {
+		len = dsname - name;
+		dsname++;
+	} else
+		dsname = "";
+	memcpy(poolname, name, len);
+	poolname[len] = '\0';
+
+	spa = spa_find_by_name(poolname);
+	if (!spa)
+		return (ENXIO);
+	rv = zfs_lookup_dataset(spa, dsname, &objid);
+	if (rv != 0)
+		return (rv);
+	rv = zfs_callback_dataset(spa, objid, zfs_set_env);
+	if (rv != 0)
+		return (rv);
+	index_str = malloc(20);
+	snprintf(index_str, 20, "%d", zfs_env_index - 1);
+	rv = setenv("bootenv_count", index_str, 1);
+	return (rv);
+}
+
+int
+zfs_set_env(const char *name)
+{
+	char *envname = NULL, *envval = NULL, *beroot;
+	int rv, i;
+
+	beroot = getenv("zfs_beroot");
+	if (beroot == NULL)
+		return (1);
+
+	envname = malloc(32);
+	envval = malloc(256);
+	/* Don't overflow the menu, shuffle entries down to show the newest */
+	if (zfs_env_index == 9) {
+		for (i = 4; i < 8; i++) {
+			snprintf(envname, 32, "bootenvmenu_caption[%d]", i);
+			snprintf(envval, 32, "bootenvmenu_caption[%d]", i + 1);
+			setenv(envname, getenv(envval), 1);
+
+			snprintf(envname, 32, "bootenvansi_caption[%d]", i);
+			snprintf(envval, 32, "bootenvansi_caption[%d]", i + 1);
+			setenv(envname, getenv(envval), 1);
+
+			snprintf(envname, 32, "bootenv_root[%d]", i);
+			snprintf(envval, 32, "bootenv_root[%d]", i + 1);
+			setenv(envname, getenv(envval), 1);
+		}
+		zfs_env_index = 8;
+	}
+
+	snprintf(envname, 32, "bootenvmenu_caption[%d]", zfs_env_index);
+	snprintf(envval, 256, "%s", name);
+	rv = setenv(envname, envval, 1);
+
+	snprintf(envname, 32, "bootenvansi_caption[%d]", zfs_env_index);
+	rv = setenv(envname, envval, 1);
+
+	snprintf(envname, 32, "bootenvmenu_command[%d]", zfs_env_index);
+	rv = setenv(envname, "set_bootenv", 1);
+
+	snprintf(envname, 32, "bootenv_root[%d]", zfs_env_index);
+	snprintf(envval, 256, "zfs:%s/%s", beroot, name);
+	rv = setenv(envname, envval, 1);
+
+	if (zfs_env_index <= 8)
+		zfs_env_index++;
+	free(envname);
+	free(envval);
+	return (rv);
+}
\ No newline at end of file
Index: sys/boot/zfs/zfsimpl.c
===================================================================
--- sys/boot/zfs/zfsimpl.c
+++ sys/boot/zfs/zfsimpl.c
@@ -1473,7 +1473,7 @@
  * the directory contents.
  */
 static int
-mzap_list(const dnode_phys_t *dnode)
+mzap_list(const dnode_phys_t *dnode, int (*callback)(const char *))
 {
 	const mzap_phys_t *mz;
 	const mzap_ent_phys_t *mze;
@@ -1492,7 +1492,7 @@
 		mze = &mz->mz_chunk[i];
 		if (mze->mze_name[0])
 			//printf("%-32s 0x%jx\n", mze->mze_name, (uintmax_t)mze->mze_value);
-			printf("%s\n", mze->mze_name);
+			callback(mze->mze_name);
 	}
 
 	return (0);
@@ -1503,7 +1503,7 @@
  * the directory header.
  */
 static int
-fzap_list(const spa_t *spa, const dnode_phys_t *dnode)
+fzap_list(const spa_t *spa, const dnode_phys_t *dnode, int (*callback)(const char *))
 {
 	int bsize = dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT;
 	zap_phys_t zh = *(zap_phys_t *) zap_scratch;
@@ -1566,13 +1566,19 @@
 			value = fzap_leaf_value(&zl, zc);
 
 			//printf("%s 0x%jx\n", name, (uintmax_t)value);
-			printf("%s\n", name);
+			callback((const char *)name);
 		}
 	}
 
 	return (0);
 }
 
+static int zfs_printf(const char *name)
+{
+	printf("%s\n", name);
+	return (0);
+}
+
 /*
  * List a zap directory.
  */
@@ -1587,9 +1593,9 @@
 
 	zap_type = *(uint64_t *) zap_scratch;
 	if (zap_type == ZBT_MICRO)
-		return mzap_list(dnode);
+		return mzap_list(dnode, zfs_printf);
 	else
-		return fzap_list(spa, dnode);
+		return fzap_list(spa, dnode, zfs_printf);
 }
 
 static int
@@ -1858,6 +1864,43 @@
 
 	return (zap_list(spa, &child_dir_zap) != 0);
 }
+
+int
+zfs_callback_dataset(const spa_t *spa, uint64_t objnum, int (*callback)(const char *name))
+{
+	uint64_t dir_obj, child_dir_zapobj, zap_type;
+	dnode_phys_t child_dir_zap, dir, dataset;
+	dsl_dataset_phys_t *ds;
+	dsl_dir_phys_t *dd;
+
+	if (objset_get_dnode(spa, &spa->spa_mos, objnum, &dataset)) {
+		printf("ZFS: can't find dataset %ju\n", (uintmax_t)objnum);
+		return (EIO);
+	}
+	ds = (dsl_dataset_phys_t *) &dataset.dn_bonus;
+	dir_obj = ds->ds_dir_obj;
+
+	if (objset_get_dnode(spa, &spa->spa_mos, dir_obj, &dir)) {
+		printf("ZFS: can't find dirobj %ju\n", (uintmax_t)dir_obj);
+		return (EIO);
+	}
+	dd = (dsl_dir_phys_t *)&dir.dn_bonus;
+
+	child_dir_zapobj = dd->dd_child_dir_zapobj;
+	if (objset_get_dnode(spa, &spa->spa_mos, child_dir_zapobj, &child_dir_zap) != 0) {
+		printf("ZFS: can't find child zap %ju\n", (uintmax_t)dir_obj);
+		return (EIO);
+	}
+
+	if (dnode_read(spa, &child_dir_zap, 0, zap_scratch, child_dir_zap.dn_datablkszsec * 512))
+		return (EIO);
+
+	zap_type = *(uint64_t *) zap_scratch;
+	if (zap_type == ZBT_MICRO)
+		return mzap_list(&child_dir_zap, callback);
+	else
+		return fzap_list(spa, &child_dir_zap, callback);
+}
 #endif
 
 /*