diff --git a/mk/functions.mk b/mk/functions.mk
index 45d91739..c48775db 100644
--- a/mk/functions.mk
+++ b/mk/functions.mk
@@ -10,5 +10,5 @@ filename-to-dep = $(dir $1).$(notdir $1).dep
 # empty string if not found.
 find-program = $(shell for i in $$(IFS=: ; echo $$PATH); do p=$$i/$(strip $1); if [ -e $$p ]; then echo $$p; break; fi; done)
 
-# Remove trailing slash.
+# Ensure that the given string ends in a single slash.
 add-trailing-slash = $(patsubst %/,%,$(1))/
diff --git a/mk/jars.mk b/mk/jars.mk
index 99470f37..c8513e66 100644
--- a/mk/jars.mk
+++ b/mk/jars.mk
@@ -1,4 +1,5 @@
 define build-jar
+
   $(1)_NAME ?= $(1)
 
   _d := $$(strip $$($(1)_DIR))
@@ -7,14 +8,20 @@ define build-jar
 
   $(1)_TMPDIR := $$(_d)/.$$($(1)_NAME).jar.tmp
 
-  $$($(1)_PATH): $$($(1)_SOURCES)
+  _jars := $$(foreach jar, $$($(1)_JARS), $$($$(jar)_PATH))
+
+  $$($(1)_PATH): $$($(1)_SOURCES) $$(_jars) $$($(1)_EXTRA_DEPS)| $$($(1)_ORDER_AFTER)
 	@rm -rf $$($(1)_TMPDIR)
 	@mkdir -p $$($(1)_TMPDIR)
-	$$(trace-javac) javac $(GLOBAL_JAVACFLAGS) $$($(1)_JAVACFLAGS) -d $$($(1)_TMPDIR) $$($(1)_SOURCES)
-	$$(trace-jar) jar cf $$($(1)_PATH) -C $$($(1)_TMPDIR) .
+	$$(trace-javac) javac $(GLOBAL_JAVACFLAGS) $$($(1)_JAVACFLAGS) -d $$($(1)_TMPDIR) \
+	  $$(foreach fn, $$($(1)_SOURCES), '$$(fn)') \
+	  -cp "$$(subst $$(space),,$$(foreach jar,$$($(1)_JARS),$$($$(jar)_PATH):))$$$$CLASSPATH"
+	@echo -e '$$(subst $$(newline),\n,$$($(1)_MANIFEST))' > $$($(1)_PATH).manifest
+	$$(trace-jar) jar cfm $$($(1)_PATH) $$($(1)_PATH).manifest -C $$($(1)_TMPDIR) .
+	@rm $$($(1)_PATH).manifest
 	@rm -rf $$($(1)_TMPDIR)
 
-  $(1)_INSTALL_DIR ?= $$(libdir)/java
+  $(1)_INSTALL_DIR ?= $$(jardir)
 
   $(1)_INSTALL_PATH := $$($(1)_INSTALL_DIR)/$$($(1)_NAME).jar
 
diff --git a/mk/lib.mk b/mk/lib.mk
index 56e162d5..ba1fb3a2 100644
--- a/mk/lib.mk
+++ b/mk/lib.mk
@@ -14,17 +14,40 @@ dist-files :=
 OS = $(shell uname -s)
 
 
+# Hack to define a literal space.
+space :=
+space +=
+
+
+# Hack to define a literal newline.
+define newline
+
+
+endef
+
+
 # Default installation paths.
 prefix ?= /usr/local
 libdir ?= $(prefix)/lib
 bindir ?= $(prefix)/bin
 libexecdir ?= $(prefix)/libexec
 datadir ?= $(prefix)/share
+jardir ?= $(datadir)/java
 localstatedir ?= $(prefix)/var
 sysconfdir ?= $(prefix)/etc
 mandir ?= $(prefix)/share/man
 
 
+# Initialise support for build directories.
+builddir ?=
+
+ifdef builddir
+  buildprefix = $(builddir)/
+else
+  buildprefix =
+endif
+
+
 # Pass -fPIC if we're building dynamic libraries.
 BUILD_SHARED_LIBS ?= 1
 
@@ -39,7 +62,6 @@ ifeq ($(BUILD_SHARED_LIBS), 1)
   SET_RPATH_TO_LIBS ?= 1
 endif
 
-
 # Pass -g if we want debug info.
 BUILD_DEBUG ?= 1
 
diff --git a/mk/libraries.mk b/mk/libraries.mk
index 3b91c699..766f7ccf 100644
--- a/mk/libraries.mk
+++ b/mk/libraries.mk
@@ -45,9 +45,9 @@ endif
 #   built, otherwise a static library.
 define build-library
   $(1)_NAME ?= $(1)
-  _d := $$(strip $$($(1)_DIR))
+  _d := $(buildprefix)$$(strip $$($(1)_DIR))
   _srcs := $$(sort $$(foreach src, $$($(1)_SOURCES), $$(src)))
-  $(1)_OBJS := $$(addsuffix .o, $$(basename $$(_srcs)))
+  $(1)_OBJS := $$(addprefix $(buildprefix), $$(addsuffix .o, $$(basename $$(_srcs))))
   _libs := $$(foreach lib, $$($(1)_LIBS), $$($$(lib)_PATH))
 
   $(1)_INSTALL_DIR ?= $$(libdir)
@@ -76,9 +76,12 @@ define build-library
     $(1)_PATH := $$(_d)/$$($(1)_NAME).$(SO_EXT)
 
     $$($(1)_PATH): $$($(1)_OBJS) $$(_libs) | $$(_d)/
-	$$(trace-ld) $(CXX) -o $$@ -shared $$(GLOBAL_LDFLAGS) $$($(1)_OBJS) $$($(1)_LDFLAGS) $$($(1)_LDFLAGS_PROPAGATED) $$(foreach lib, $$($(1)_LIBS), $$($$(lib)_LDFLAGS_USE))
+	$$(trace-ld) $(CXX) -o $$(abspath $$@) -shared $$(GLOBAL_LDFLAGS) $$($(1)_OBJS) $$($(1)_LDFLAGS) $$($(1)_LDFLAGS_PROPAGATED) $$(foreach lib, $$($(1)_LIBS), $$($$(lib)_LDFLAGS_USE)) $$($(1)_LDFLAGS_UNINSTALLED)
 
-    $(1)_LDFLAGS_USE += -L$$(_d) -Wl,-rpath,$$(abspath $$(_d)) -l$$(patsubst lib%,%,$$(strip $$($(1)_NAME)))
+    ifneq ($(OS), Darwin)
+      $(1)_LDFLAGS_USE += -Wl,-rpath,$$(abspath $$(_d))
+    endif
+    $(1)_LDFLAGS_USE += -L$$(_d) -l$$(patsubst lib%,%,$$(strip $$($(1)_NAME)))
 
     $(1)_INSTALL_PATH := $(DESTDIR)$$($(1)_INSTALL_DIR)/$$($(1)_NAME).$(SO_EXT)
 
@@ -90,10 +93,12 @@ define build-library
 	$$(trace-ld) $(CXX) -o $$@ -shared $$(GLOBAL_LDFLAGS) $$($(1)_OBJS) $$($(1)_LDFLAGS) $$($(1)_LDFLAGS_PROPAGATED) $$(foreach lib, $$($(1)_LIBS), $$($$(lib)_LDFLAGS_USE_INSTALLED))
 
     $(1)_LDFLAGS_USE_INSTALLED += -L$$(DESTDIR)$$($(1)_INSTALL_DIR) -l$$(patsubst lib%,%,$$(strip $$($(1)_NAME)))
-    ifeq ($(SET_RPATH_TO_LIBS), 1)
-      $(1)_LDFLAGS_USE_INSTALLED += -Wl,-rpath,$$($(1)_INSTALL_DIR)
-    else
-      $(1)_LDFLAGS_USE_INSTALLED += -Wl,-rpath-link,$$($(1)_INSTALL_DIR)
+    ifneq ($(OS), Darwin)
+      ifeq ($(SET_RPATH_TO_LIBS), 1)
+        $(1)_LDFLAGS_USE_INSTALLED += -Wl,-rpath,$$($(1)_INSTALL_DIR)
+      else
+        $(1)_LDFLAGS_USE_INSTALLED += -Wl,-rpath-link,$$($(1)_INSTALL_DIR)
+      endif
     endif
 
     ifdef $(1)_FORCE_INSTALL
diff --git a/mk/patterns.mk b/mk/patterns.mk
index 6b2cfd01..3219d962 100644
--- a/mk/patterns.mk
+++ b/mk/patterns.mk
@@ -1,8 +1,11 @@
-%.o: %.cc
+$(buildprefix)%.o: %.cc
+	@mkdir -p "$(dir $@)"
 	$(trace-cxx) $(CXX) -o $@ -c $< $(GLOBAL_CXXFLAGS) $(GLOBAL_CXXFLAGS_PCH) $(CXXFLAGS) $($@_CXXFLAGS) -MMD -MF $(call filename-to-dep, $@) -MP
 
-%.o: %.cpp
+$(buildprefix)%.o: %.cpp
+	@mkdir -p "$(dir $@)"
 	$(trace-cxx) $(CXX) -o $@ -c $< $(GLOBAL_CXXFLAGS) $(GLOBAL_CXXFLAGS_PCH) $(CXXFLAGS) $($@_CXXFLAGS) -MMD -MF $(call filename-to-dep, $@) -MP
 
-%.o: %.c
+$(buildprefix)%.o: %.c
+	@mkdir -p "$(dir $@)"
 	$(trace-cc) $(CC) -o $@ -c $< $(GLOBAL_CFLAGS) $(CFLAGS) $($@_CFLAGS) -MMD -MF $(call filename-to-dep, $@) -MP
diff --git a/mk/programs.mk b/mk/programs.mk
index 72afdf95..3ac64494 100644
--- a/mk/programs.mk
+++ b/mk/programs.mk
@@ -23,9 +23,9 @@ programs-list :=
 # - $(1)_INSTALL_DIR: the directory where the program will be
 #   installed; defaults to $(bindir).
 define build-program
-  _d := $$($(1)_DIR)
+  _d := $(buildprefix)$$($(1)_DIR)
   _srcs := $$(sort $$(foreach src, $$($(1)_SOURCES), $$(src)))
-  $(1)_OBJS := $$(addsuffix .o, $$(basename $$(_srcs)))
+  $(1)_OBJS := $$(addprefix $(buildprefix), $$(addsuffix .o, $$(basename $$(_srcs))))
   _libs := $$(foreach lib, $$($(1)_LIBS), $$($$(lib)_PATH))
   $(1)_PATH := $$(_d)/$(1)
 
diff --git a/mk/templates.mk b/mk/templates.mk
index ab99168b..c7ac7afb 100644
--- a/mk/templates.mk
+++ b/mk/templates.mk
@@ -8,8 +8,12 @@ define instantiate-template
 
 endef
 
+ifneq ($(MAKECMDGOALS), clean)
+
 %.h: %.h.in
 	$(trace-gen) rm -f $@ && ./config.status --quiet --header=$@
 
 %: %.in
 	$(trace-gen) rm -f $@ && ./config.status --quiet --file=$@
+
+endif