diff --git a/Makefile.inc1 b/Makefile.inc1
index 19a252673dab..66816ceb5fa2 100644
--- a/Makefile.inc1
+++ b/Makefile.inc1
@@ -1030,12 +1030,12 @@ _prebuild_libs=	${_kerberos5_lib_libasn1} ${_kerberos5_lib_libkrb5} \
 		${_secure_lib_libcrypto} ${_secure_lib_libssh} \
 		${_secure_lib_libssl}
 
-.if ${MK_LIBTHR} != "no" && ${MK_LIBPTHREAD} != "no"
+.if ${MK_LIBTHR} != "no" && ${MK_LIBKSE} != "no" && ${MK_LIBPTHREAD} != "no"
 _default_thread_lib=	lib/${DEFAULT_THREAD_LIB}
 .elif ${MK_LIBTHR} != "no"
 _default_thread_lib=	lib/libthr
-.elif ${MK_LIBPTHREAD} != "no"
-_default_thread_lib=	lib/libpthread
+.elif ${MK_LIBKSE} != "no"
+_default_thread_lib=	lib/libkse
 .endif
 
 _generic_libs=	${_cddl_lib} gnu/lib ${_kerberos5_lib} lib ${_secure_lib} usr.bin/lex/lib
diff --git a/UPDATING b/UPDATING
index 107c03110bd3..9ba4ddc1c141 100644
--- a/UPDATING
+++ b/UPDATING
@@ -21,6 +21,10 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 7.x IS SLOW:
 	developers choose to disable these features on build machines
 	to maximize performance.
 
+20071008:
+	Setting WITHOUT_LIBPTHREAD now means WITHOUT_LIBKSE and
+	WITHOUT_LIBTHR are set.
+
 20070930:
 	The PCI code has been made aware of PCI domains. This means that
 	the location strings as used by pciconf(8) etc are now in the
@@ -145,9 +149,9 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 7.x IS SLOW:
 	which previously had symbol dependencies to FBSD_1.0, will fail
 	because the freshly installed libc will not have them.
 
-	The default threading library has been changed to libthr.  If
-	you wish to have libpthread as your default, use option
-	DEFAULT_THREAD_LIB=libpthread for the buildworld.
+	The default threading library (providing "libpthread") has been
+	changed to libthr.  If you wish to have libkse as your default,
+	use option DEFAULT_THREAD_LIB=libkse for the buildworld.
 
 20070423:
 	The ABI breakage in sendmail(8)'s libmilter has been repaired
diff --git a/cddl/lib/Makefile b/cddl/lib/Makefile
index 138f60740ee3..f517dfe109d1 100644
--- a/cddl/lib/Makefile
+++ b/cddl/lib/Makefile
@@ -11,7 +11,7 @@ SUBDIR=	libavl \
 
 .if ${MK_ZFS} != "no"
 _libzfs=	libzfs
-.if ${MK_LIBTHR} != "no" || ${MK_LIBPTHREAD} != "no"
+.if ${MK_LIBTHR} != "no" || ${MK_LIBKSE} != "no" || ${MK_LIBPTHREAD} != "no"
 _libzpool=	libzpool
 .endif
 .endif
diff --git a/cddl/usr.bin/Makefile b/cddl/usr.bin/Makefile
index 2ca99cbe1092..0ec531020c52 100644
--- a/cddl/usr.bin/Makefile
+++ b/cddl/usr.bin/Makefile
@@ -5,7 +5,7 @@
 SUBDIR=	${_ztest}
 
 .if ${MK_ZFS} != "no"
-.if ${MK_LIBTHR} != "no" || ${MK_LIBPTHREAD} != "no"
+.if ${MK_LIBPTHREAD} != "no" && (${MK_LIBTHR} != "no" || ${MK_LIBKSE} != "no")
 _ztest=	ztest
 .endif
 .endif
diff --git a/cddl/usr.sbin/Makefile b/cddl/usr.sbin/Makefile
index f8b81fcdd1f1..5caee344521d 100644
--- a/cddl/usr.sbin/Makefile
+++ b/cddl/usr.sbin/Makefile
@@ -5,7 +5,7 @@
 SUBDIR=	${_zdb}
 
 .if ${MK_ZFS} != "no"
-.if ${MK_LIBTHR} != "no" || ${MK_LIBPTHREAD} != "no"
+.if ${MK_LIBPTHREAD} != "no" && (${MK_LIBTHR} != "no" || ${MK_LIBKSE} != "no")
 _zdb=	zdb
 .endif
 .endif
diff --git a/lib/Makefile b/lib/Makefile
index 890c3bc6cad0..0f4515133c04 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -34,7 +34,7 @@ SUBDIR=	${_csu} libc libbsm libcom_err libcrypt libelf libkvm msun libmd \
 	libgssapi libipsec \
 	${_libipx} libkiconv libmagic libmemstat ${_libmilter} ${_libmp} \
 	${_libncp} ${_libngatm} libopie libpam libpcap \
-	libpmc ${_libpthread} librt ${_libsdp} ${_libsm} ${_libsmb} \
+	libpmc ${_libkse} librt ${_libsdp} ${_libsm} ${_libsmb} \
 	${_libsmdb} \
 	${_libsmutil} libstand libtelnet ${_libthr} ${_libthread_db} libufs \
 	libugidfw ${_libusbhid} ${_libvgl} libwrap liby libz ${_bind}
@@ -101,11 +101,13 @@ _libsmb=	libsmb
 .endif
 
 .if ${MK_LIBPTHREAD} != "no"
-_libpthread=	libpthread
+.if ${MK_LIBKSE} != "no"
+_libkse=	libkse
 .endif
 
 .if ${MK_LIBTHR} != "no"
-_libthr= libthr
+_libthr=	libthr
+.endif
 .endif
 
 .if ${MACHINE_ARCH} != "arm"
diff --git a/lib/libkse/Makefile b/lib/libkse/Makefile
index ed80d758acca..7c7f8f285a09 100644
--- a/lib/libkse/Makefile
+++ b/lib/libkse/Makefile
@@ -10,13 +10,13 @@
 
 .include <bsd.own.mk>
 
-.if (${DEFAULT_THREAD_LIB} == "libpthread" || ${MK_LIBTHR} == "no") && \
+.if (${DEFAULT_THREAD_LIB} == "libkse" || ${MK_LIBTHR} == "no") && \
     ${SHLIBDIR} == "/usr/lib"
 SHLIBDIR= /lib
 .endif
 
 LIB=kse
-SHLIB_MAJOR= 3
+SHLIB_MAJOR= 0
 CFLAGS+=-DPTHREAD_KERNEL
 CFLAGS+=-I${.CURDIR}/../libc/include -I${.CURDIR}/thread \
 	-I${.CURDIR}/../../include
@@ -26,7 +26,7 @@ CFLAGS+=-I${.CURDIR}/../../libexec/rtld-elf
 CFLAGS+=-I${.CURDIR}/../../libexec/rtld-elf/${MACHINE_ARCH}
 CFLAGS+=-fno-builtin
 
-# Uncomment this if you want libpthread to contain debug information for
+# Uncomment this if you want libkse to contain debug information for
 # thread locking.
 CFLAGS+=-D_LOCK_DEBUG
 WARNS?=2
@@ -38,7 +38,7 @@ WARNS?=2
 # Enable extra internal consistancy checks.
 CFLAGS+=-D_PTHREADS_INVARIANTS -Wall
 
-VERSION_MAP=${.CURDIR}/pthread.map
+VERSION_MAP=${.CURDIR}/kse.map
 
 PRECIOUSLIB=
 
@@ -47,7 +47,7 @@ PRECIOUSLIB=
 .include "${.CURDIR}/sys/Makefile.inc"
 .include "${.CURDIR}/thread/Makefile.inc"
 
-.if ${DEFAULT_THREAD_LIB} == "libpthread" || ${MK_LIBTHR} == "no"
+.if ${DEFAULT_THREAD_LIB} == "libkse" || ${MK_LIBTHR} == "no"
 SYMLINKS+=lib${LIB}.a ${LIBDIR}/libpthread.a
 .if !defined(NO_PIC)
 SYMLINKS+=lib${LIB}.so ${LIBDIR}/libpthread.so
diff --git a/lib/libpthread/pthread.map b/lib/libkse/kse.map
similarity index 99%
rename from lib/libpthread/pthread.map
rename to lib/libkse/kse.map
index 1f2787ca25fd..e8888df5fba7 100644
--- a/lib/libpthread/pthread.map
+++ b/lib/libkse/kse.map
@@ -1,6 +1,4 @@
-/*
- * $FreeBSD$
- */
+/* $FreeBSD$ */
 
 /*
  * Use the same naming scheme as libc.
diff --git a/lib/libkse/test/guard_b.exp b/lib/libkse/test/guard_b.exp
index 8e5b9e426a21..cc6747094a15 100644
--- a/lib/libkse/test/guard_b.exp
+++ b/lib/libkse/test/guard_b.exp
@@ -1,3 +1,4 @@
+# $FreeBSD$
 Test begin
 No overflow:
 Overflow:
diff --git a/lib/libkse/test/hello_d.exp b/lib/libkse/test/hello_d.exp
index 802992c4220d..47be080f357a 100644
--- a/lib/libkse/test/hello_d.exp
+++ b/lib/libkse/test/hello_d.exp
@@ -1 +1,2 @@
+# $FreeBSD$
 Hello world
diff --git a/lib/libkse/test/join_leak_d.exp b/lib/libkse/test/join_leak_d.exp
index 369a88dd2404..a54de72b8908 100644
--- a/lib/libkse/test/join_leak_d.exp
+++ b/lib/libkse/test/join_leak_d.exp
@@ -1,2 +1,3 @@
+# $FreeBSD$
 Test begin
 Test end
diff --git a/lib/libkse/test/mutex_d.exp b/lib/libkse/test/mutex_d.exp
index de8a4e42d8e2..dd2f7bd1e526 100644
--- a/lib/libkse/test/mutex_d.exp
+++ b/lib/libkse/test/mutex_d.exp
@@ -1,3 +1,4 @@
+# $FreeBSD$
 
 Testing pthread_mutex_init
 --------------------------
diff --git a/lib/libkse/test/sem_d.exp b/lib/libkse/test/sem_d.exp
index b0de3da1f5e6..cd86f1241109 100644
--- a/lib/libkse/test/sem_d.exp
+++ b/lib/libkse/test/sem_d.exp
@@ -1,3 +1,4 @@
+# $FreeBSD$
 Test begin
 Got semaphore
 Got semaphore
diff --git a/lib/libkse/test/sigsuspend_d.exp b/lib/libkse/test/sigsuspend_d.exp
index 901fa50dd2d1..03c9a727799e 100644
--- a/lib/libkse/test/sigsuspend_d.exp
+++ b/lib/libkse/test/sigsuspend_d.exp
@@ -1,3 +1,4 @@
+# $FreeBSD$
   -> Suspender thread signal handler caught signal 16
 Sigsuspend woke up by signal 16
   -> Suspender thread signal handler caught signal 16
diff --git a/lib/libkse/test/sigwait_d.exp b/lib/libkse/test/sigwait_d.exp
index 2e9b2c492525..b9245be31f0e 100644
--- a/lib/libkse/test/sigwait_d.exp
+++ b/lib/libkse/test/sigwait_d.exp
@@ -1,3 +1,4 @@
+# $FreeBSD$
 Sigwait caught signal 16
 Sigwait caught signal 16
 Sigwait caught signal 30
diff --git a/lib/libpthread/Makefile b/lib/libpthread/Makefile
deleted file mode 100644
index ed80d758acca..000000000000
--- a/lib/libpthread/Makefile
+++ /dev/null
@@ -1,60 +0,0 @@
-# $FreeBSD$
-#
-# All library objects contain FreeBSD revision strings by default; they may be
-# excluded as a space-saving measure.  To produce a library that does
-# not contain these strings, add -DSTRIP_FBSDID (see <sys/cdefs.h>) to CFLAGS
-# below.  Note, there are no IDs for syscall stubs whose sources are generated.
-# To included legacy CSRG sccsid strings, add -DLIBC_SCCS and -DSYSLIBC_SCCS
-# (for system call stubs) to CFLAGS below.  -DSYSLIBC_SCCS affects just the
-# system call stubs.
-
-.include <bsd.own.mk>
-
-.if (${DEFAULT_THREAD_LIB} == "libpthread" || ${MK_LIBTHR} == "no") && \
-    ${SHLIBDIR} == "/usr/lib"
-SHLIBDIR= /lib
-.endif
-
-LIB=kse
-SHLIB_MAJOR= 3
-CFLAGS+=-DPTHREAD_KERNEL
-CFLAGS+=-I${.CURDIR}/../libc/include -I${.CURDIR}/thread \
-	-I${.CURDIR}/../../include
-CFLAGS+=-I${.CURDIR}/arch/${MACHINE_ARCH}/include
-CFLAGS+=-I${.CURDIR}/sys
-CFLAGS+=-I${.CURDIR}/../../libexec/rtld-elf
-CFLAGS+=-I${.CURDIR}/../../libexec/rtld-elf/${MACHINE_ARCH}
-CFLAGS+=-fno-builtin
-
-# Uncomment this if you want libpthread to contain debug information for
-# thread locking.
-CFLAGS+=-D_LOCK_DEBUG
-WARNS?=2
-
-# Uncomment this if you want to build a 1:1 threading mode library
-# however it is no longer strictly conformed to POSIX
-# CFLAGS+=-DSYSTEM_SCOPE_ONLY
-
-# Enable extra internal consistancy checks.
-CFLAGS+=-D_PTHREADS_INVARIANTS -Wall
-
-VERSION_MAP=${.CURDIR}/pthread.map
-
-PRECIOUSLIB=
-
-.include "${.CURDIR}/arch/${MACHINE_ARCH}/Makefile.inc"
-.include "${.CURDIR}/support/Makefile.inc"
-.include "${.CURDIR}/sys/Makefile.inc"
-.include "${.CURDIR}/thread/Makefile.inc"
-
-.if ${DEFAULT_THREAD_LIB} == "libpthread" || ${MK_LIBTHR} == "no"
-SYMLINKS+=lib${LIB}.a ${LIBDIR}/libpthread.a
-.if !defined(NO_PIC)
-SYMLINKS+=lib${LIB}.so ${LIBDIR}/libpthread.so
-.endif
-.if ${MK_PROFILE} != "no"
-SYMLINKS+=lib${LIB}_p.a ${LIBDIR}/libpthread_p.a
-.endif
-.endif
-
-.include <bsd.lib.mk>
diff --git a/sbin/ggate/Makefile b/sbin/ggate/Makefile
index 7ab5ccb9aede..e889f2fafad3 100644
--- a/sbin/ggate/Makefile
+++ b/sbin/ggate/Makefile
@@ -6,7 +6,7 @@ SUBDIR=	${_ggatec} \
 	${_ggated} \
 	ggatel
 
-.if ${MK_LIBTHR} != "no" || ${MK_LIBPTHREAD} != "no"
+.if ${MK_LIBPTHREAD} != "no" && (${MK_LIBTHR} != "no" || ${MK_LIBKSE} != "no")
 _ggatec=	ggatec
 _ggated=	ggated
 .endif
diff --git a/share/man/man3/Makefile b/share/man/man3/Makefile
index fcc94ef3dfbc..5ff093fb887f 100644
--- a/share/man/man3/Makefile
+++ b/share/man/man3/Makefile
@@ -146,7 +146,7 @@ MLINKS+=	tree.3 RB_EMPTY.3 \
 		tree.3 SPLAY_RIGHT.3 \
 		tree.3 SPLAY_ROOT.3
 
-.if ${MK_LIBPTHREAD} != "no" || ${MK_LIBTHR} != "no"
+.if ${MK_LIBPTHREAD} != "no" && (${MK_LIBTHR} != "no" || ${MK_LIBKSE} != "no")
 PTHREAD_MAN=	pthread.3 \
 		pthread_atfork.3 \
 		pthread_attr.3 \
diff --git a/share/man/man5/src.conf.5 b/share/man/man5/src.conf.5
index 68c94570794b..3a38aeff7660 100644
--- a/share/man/man5/src.conf.5
+++ b/share/man/man5/src.conf.5
@@ -379,10 +379,10 @@ support.
 On amd64, set to not build 32-bit library set and a
 .Nm ld-elf32.so.1
 runtime linker.
-.It Va WITHOUT_LIBPTHREAD
-.\" from FreeBSD: src/tools/build/options/WITHOUT_LIBPTHREAD,v 1.1 2006/03/21 07:50:50 ru Exp
+.It Va WITHOUT_LIBKSE
+.\" from FreeBSD: src/tools/build/options/WITHOUT_LIBKSE,v 1.1 2006/03/21 07:50:50 obrien Exp
 Set to not build the
-.Nm libpthread
+.Nm libkse
 (M:N threading)
 library.
 .It Va WITHOUT_LIBTHR
@@ -391,6 +391,15 @@ Set to not build the
 .Nm libthr
 (1:1 threading)
 library.
+.It Va WITHOUT_LIBPTHREAD
+.\" from FreeBSD: src/tools/build/options/WITHOUT_LIBPTHREAD,v 1.1 2006/03/21 07:50:50 ru Exp
+Set to not build either of the
+.Nm libpthread
+providing libraries (
+.Nm libthr
+(1:1) &
+.Nm libkse
+(M:N)).
 .It Va WITHOUT_LOCALES
 .\" from FreeBSD: src/tools/build/options/WITHOUT_LOCALES,v 1.1 2006/03/21 07:50:50 ru Exp
 Set to not build localization files; see
diff --git a/share/mk/bsd.compat.mk b/share/mk/bsd.compat.mk
index dfa5dfc53e2d..5c3a8755b8f0 100644
--- a/share/mk/bsd.compat.mk
+++ b/share/mk/bsd.compat.mk
@@ -16,6 +16,7 @@
 	NOINFOCOMPRESS:NO_INFOCOMPRESS \
 	NOINSTALLLIB:NO_INSTALLLIB \
 	NOLIBPTHREAD:NO_LIBPTHREAD \
+	NOLIBKSE:NO_LIBKSE \
 	NOLIBTHR:NO_LIBTHR \
 	NOLINT:NO_LINT \
 	NOMAN:NO_MAN \
diff --git a/share/mk/bsd.own.mk b/share/mk/bsd.own.mk
index b3f431bad661..92f3b3b0a219 100644
--- a/share/mk/bsd.own.mk
+++ b/share/mk/bsd.own.mk
@@ -239,6 +239,7 @@ WITHOUT_${var}=
     KERBEROS \
     LIB32 \
     LIBPTHREAD \
+    LIBKSE \
     LIBTHR \
     LOCALES \
     LPR \
@@ -328,6 +329,7 @@ WITH_IDEA=
     KVM \
     LIB32 \
     LIBPTHREAD \
+    LIBKSE \
     LIBTHR \
     LOCALES \
     LPR \
diff --git a/tools/build/mk/OptionalObsoleteFiles.inc b/tools/build/mk/OptionalObsoleteFiles.inc
index 87550da48101..a5e004bc4eb7 100644
--- a/tools/build/mk/OptionalObsoleteFiles.inc
+++ b/tools/build/mk/OptionalObsoleteFiles.inc
@@ -904,7 +904,7 @@ OLD_FILES+=usr/share/man/man8/ktutil.8.gz
 # to be filled in
 #.endif
 
-#.if ${MK_LIBPTHREAD} == no
+#.if ${MK_LIBKSE} == no
 # to be filled in
 #.endif
 
diff --git a/tools/build/options/WITHOUT_LIBKSE b/tools/build/options/WITHOUT_LIBKSE
new file mode 100644
index 000000000000..28a3fd8a2aed
--- /dev/null
+++ b/tools/build/options/WITHOUT_LIBKSE
@@ -0,0 +1,5 @@
+.\" $FreeBSD$
+Set to not build the
+.Nm libpthread
+(M:N threading)
+library.
diff --git a/tools/build/options/WITHOUT_LIBPTHREAD b/tools/build/options/WITHOUT_LIBPTHREAD
index 28a3fd8a2aed..88320c0aa321 100644
--- a/tools/build/options/WITHOUT_LIBPTHREAD
+++ b/tools/build/options/WITHOUT_LIBPTHREAD
@@ -1,5 +1,8 @@
 .\" $FreeBSD$
-Set to not build the
+Set to not build either of the
 .Nm libpthread
-(M:N threading)
-library.
+providing libraries (
+.Nm libthr
+(1:1) &
+.Nm libkse
+(M:N)).
diff --git a/usr.bin/Makefile b/usr.bin/Makefile
index 90cab4c7e5f9..ebc5d4c3715b 100644
--- a/usr.bin/Makefile
+++ b/usr.bin/Makefile
@@ -260,7 +260,7 @@ _calendar=	calendar
 .if ${MK_OPENSSL} != "no"
 _chkey=		chkey
 _newkey=	newkey
-.if ${MK_LIBTHR} != "no" || ${MK_LIBPTHREAD} != "no"
+.if ${MK_LIBPTHREAD} != "no" && (${MK_LIBTHR} != "no" || ${MK_LIBKSE} != "no")
 _csup=		csup
 .endif
 .endif
diff --git a/usr.sbin/Makefile b/usr.sbin/Makefile
index 066ffa09e53a..c4bfd256ed3a 100644
--- a/usr.sbin/Makefile
+++ b/usr.sbin/Makefile
@@ -268,7 +268,7 @@ _ypset=		ypset
 _authpf=	authpf
 .endif
 
-.if ${MK_LIBTHR} != "no" || ${MK_LIBPTHREAD} != "no"
+.if ${MK_LIBPTHREAD} != "no" && (${MK_LIBTHR} != "no" || ${MK_LIBKSE} != "no")
 _pppctl=	pppctl
 .endif
 
@@ -277,7 +277,7 @@ _lpr=		lpr
 .endif
 
 .if ${MK_NS_CACHING} != "no"
-.if ${MK_LIBTHR} != "no" || ${MK_LIBPTHREAD} != "no"
+.if ${MK_LIBPTHREAD} != "no" && (${MK_LIBTHR} != "no" || ${MK_LIBKSE} != "no")
 _nscd=		nscd
 .endif
 .endif
diff --git a/usr.sbin/ngctl/Makefile b/usr.sbin/ngctl/Makefile
index cf17d2eb8005..1a9e50b74676 100644
--- a/usr.sbin/ngctl/Makefile
+++ b/usr.sbin/ngctl/Makefile
@@ -13,7 +13,7 @@ WARNS?=	3
 NGCTL_NO_LIBEDIT=
 .endif
 
-.if ${MK_LIBTHR} == "no" && ${MK_LIBPTHREAD} == "no"
+.if ${MK_LIBPTHREAD} == "no" && ${MK_LIBTHR} == "no" && ${MK_LIBKSE}
 NGCTL_NO_LIBEDIT=
 .endif