diff --git a/.gitignore b/.gitignore
index 0471c9b2..a422a329 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,19 +1,12 @@
-# Intermediate files directory.
+# Build outputs.
+bin/
+lib/
+wren
+
+# Intermediate files.
 build/
 .sass-cache/
 
-# Built files at the top level.
-wren
-wrend
-wren-cpp
-libwren.a
-libwrend.a
-libwren.so
-libwrend.so
-libwren.dylib
-libwrend.dylib
-libwren-cpp.a
-
 # XCode user-specific stuff.
 xcuserdata/
 *.xccheckout
diff --git a/Makefile b/Makefile
index 01de1ab8..dd210eb5 100644
--- a/Makefile
+++ b/Makefile
@@ -1,124 +1,56 @@
-AR := ar rcu
-# Compiler flags.
-CFLAGS := -std=c99 -Wall -Werror
-# TODO: Add -Wextra.
-CPPFLAGS := -std=c++98 -Wall -Werror
-DEBUG_CFLAGS := -O0 -DDEBUG -g
-RELEASE_CFLAGS := -Os
+# Top-level Makefile. This has targets for various utility things. To actually
+# compile Wren itself, it invokes script/wren.mk for the various configurations
+# that Wren can be built with.
 
-# Detect the OS.
-TARGET_OS := $(lastword $(subst -, ,$(shell $(CC) -dumpmachine)))
+# Executables are built to bin/. Libraries are built to lib/.
 
-# Don't add -fPIC on Windows since it generates a warning which gets promoted
-# to an error by -Werror.
-ifeq      ($(TARGET_OS),mingw32)
-else ifeq ($(TARGET_OS),cygwin)
-	# Do nothing.
-else
-	CFLAGS += -fPIC
-	CPPFLAGS += -fPIC
-endif
+# A normal, optimized release build for the current CPU architecture.
+release:
+	@ $(MAKE) -f script/wren.mk
+	@ cp bin/wren wren # For convenience, copy the interpreter to the top level.
 
-# Clang on Mac OS X has different flags and a different extension to build a
-# shared library.
-ifneq (,$(findstring darwin,$(TARGET_OS)))
-	SHARED_LIB_FLAGS =
-	SHARED_EXT = dylib
-else
-	SHARED_LIB_FLAGS = -Wl,-soname,$@.so
-	SHARED_EXT = so
-endif
+# A debug build for the current architecture.
+debug:
+	@ $(MAKE) -f script/wren.mk MODE=debug
 
-# Files.
-SOURCES := $(wildcard src/*.c)
-HEADERS := $(wildcard src/*.h)
-OBJECTS := $(SOURCES:.c=.o)
-
-# Don't include main.c in the libraries.
-DEBUG_OBJECTS := $(addprefix build/debug/, $(notdir $(OBJECTS)))
-RELEASE_OBJECTS := $(addprefix build/release/, $(notdir $(OBJECTS)))
-RELEASE_CPP_OBJECTS := $(addprefix build/release-cpp/, $(notdir $(OBJECTS)))
-
-DEBUG_LIB_OBJECTS := $(subst build/debug/main.o,,$(DEBUG_OBJECTS))
-RELEASE_LIB_OBJECTS := $(subst build/release/main.o,,$(RELEASE_OBJECTS))
-RELEASE_CPP_LIB_OBJECTS := $(subst build/release-cpp/main.o,,$(RELEASE_CPP_OBJECTS))
-
-.PHONY: all clean test builtin docs watchdocs prep
-
-all: release
+# Build all configurations.
+all: debug release
+	@ $(MAKE) -f script/wren.mk LANG=cpp
+	@ $(MAKE) -f script/wren.mk MODE=debug LANG=cpp
+	@ $(MAKE) -f script/wren.mk ARCH=32
+	@ $(MAKE) -f script/wren.mk LANG=cpp ARCH=32
+	@ $(MAKE) -f script/wren.mk MODE=debug ARCH=32
+	@ $(MAKE) -f script/wren.mk MODE=debug LANG=cpp ARCH=32
+	@ $(MAKE) -f script/wren.mk ARCH=64
+	@ $(MAKE) -f script/wren.mk LANG=cpp ARCH=64
+	@ $(MAKE) -f script/wren.mk MODE=debug ARCH=64
+	@ $(MAKE) -f script/wren.mk MODE=debug LANG=cpp ARCH=64
 
+# Remove all build outputs and intermediate files.
 clean:
-	@rm -rf build
-	@rm -rf wren libwren.a libwren.so libwren.dylib
-	@rm -rf wrend libwrend.a libwrend.so libwrend.dylib
-
-prep:
-	@mkdir -p build/debug build/release build/release-cpp
-
-# Debug build.
-debug: prep wrend libwrend
-
-# Debug static and shared libraries.
-libwrend: $(DEBUG_LIB_OBJECTS)
-	$(AR) $@.a $^
-	$(CC) $(DEBUG_CFLAGS) -shared $(SHARED_LIB_FLAGS) -o $@.$(SHARED_EXT) $^
-
-# Debug command-line interpreter.
-wrend: $(DEBUG_OBJECTS)
-	$(CC) $(CFLAGS) $(DEBUG_CFLAGS) -Iinclude -o $@ $^ -lm
-
-# Debug object files.
-build/debug/%.o: src/%.c include/wren.h $(HEADERS)
-	$(CC) -c $(CFLAGS) $(DEBUG_CFLAGS) -Iinclude -o $@ $<
-
-# Release build.
-release: prep wren libwren
-
-# Release static and shared libraries.
-libwren: $(RELEASE_LIB_OBJECTS)
-	$(AR) $@.a $^
-	$(CC) $(RELEASE_CFLAGS) -shared $(SHARED_LIB_FLAGS) -o $@.$(SHARED_EXT) $^
-
-# Release command-line interpreter.
-wren: $(RELEASE_OBJECTS)
-	$(CC) $(CFLAGS) $(RELEASE_CFLAGS) -Iinclude -o $@ $^ -lm
-
-# Release object files.
-build/release/%.o: src/%.c include/wren.h $(HEADERS)
-	$(CC) -c $(CFLAGS) $(RELEASE_CFLAGS) -Iinclude -o $@ $<
-
-# Release C++ build.
-release-cpp: prep wren-cpp libwren-cpp
-
-# Release C++ static library.
-libwren-cpp: $(RELEASE_CPP_LIB_OBJECTS)
-	$(AR) $@.a $^
-
-# Release C++ command-line interpreter.
-wren-cpp: $(RELEASE_CPP_OBJECTS)
-	$(CC) $(CPPFLAGS) $(RELEASE_CFLAGS) -Iinclude -o $@ $^ -lm
-
-# Release C++ object files.
-build/release-cpp/%.o: src/%.c include/wren.h $(HEADERS)
-	$(CC) -c $(CPPFLAGS) $(RELEASE_CFLAGS) -Iinclude -o $@ -x c++ $<
+	@ rm -rf bin
+	@ rm -rf build
+	@ rm -rf lib
 
 # Run the tests against the debug build of Wren.
 test: debug
-	@./script/test.py $(suite)
+	@ ./script/test.py $(suite)
 
 # Take the contents of the scripts under builtin/ and copy them into their
 # respective wren_<name>.c source files.
 builtin:
-	@./script/generate_builtins.py
+	@ ./script/generate_builtins.py
 
 # Generate the Wren site.
 docs:
-	@./script/generate_docs.py
+	@ ./script/generate_docs.py
 
 # Continuously generate the Wren site.
 watchdocs:
-	@./script/generate_docs.py --watch
+	@ ./script/generate_docs.py --watch
 
 # Build the docs and copy them to a local "gh-pages" directory.
 gh-pages: docs
-	cp -r build/docs/. gh-pages
+	@ cp -r build/docs/. gh-pages
+
+.PHONY: debug release all clean test builtin docs watchdocs gh-pages
diff --git a/doc/site/getting-started.markdown b/doc/site/getting-started.markdown
index dc9fcc04..42e20bce 100644
--- a/doc/site/getting-started.markdown
+++ b/doc/site/getting-started.markdown
@@ -10,6 +10,9 @@ Mac and you can rock a command line, it's just:
     $ make
     $ ./wren
 
+Binaries for other configurations are built to `bin/`. Static and shared
+libraries for embedding Wren get built in `lib/`.
+
 For Mac users, there is also an XCode project under `project/xcode`. For
 Windows brethren, `project/msvc2013` contains a Visual Studio solution. Note
 that these may not have the exact same build settings as the makefile. The
diff --git a/script/wren.mk b/script/wren.mk
new file mode 100644
index 00000000..ef77e2ad
--- /dev/null
+++ b/script/wren.mk
@@ -0,0 +1,108 @@
+# Makefile for building a single configuration of Wren. It allows the
+# following variables to be passed to it:
+#
+# MODE - The build mode, "debug" or "release".
+#				 If omitted, defaults to "release".
+# LANG - The language, "c" or "cpp".
+# 		   If omitted, defaults to "c".
+# ARCH - The processor architecture, "32", "64", or nothing, which indicates
+#				 the compiler's default.
+#        If omitted, defaults to the compiler's default.
+#
+# It builds a static library, shared library, and command-line interpreter for
+# the given configuration. Libraries are built to "lib", and the interpreter
+# is built to "bin".
+#
+# The output file is initially "wren". If in debug mode, "d" is appended to it.
+# If the language is "cpp", then "-cpp" is appended to that. If the
+# architecture is not the default then "-32" or "-64" is appended to that.
+# Then, for the libraries, the correct extension is added.
+
+# Files.
+HEADERS   := include/wren.h $(wildcard src/*.h)
+SOURCES   := $(wildcard src/*.c)
+BUILD_DIR := build
+
+CFLAGS := -Wall -Werror
+# TODO: Add -Wextra.
+
+# Mode configuration.
+ifeq ($(MODE),debug)
+	WREN := wrend
+	CFLAGS += -O0 -DDEBUG -g
+	BUILD_DIR := $(BUILD_DIR)/debug
+else
+	WREN += wren
+	CFLAGS += -Os
+	BUILD_DIR := $(BUILD_DIR)/release
+endif
+
+# Language configuration.
+ifeq ($(LANG),cpp)
+	WREN := $(WREN)-cpp
+	CFLAGS += -std=c++98
+	FILE_FLAG := -x c++
+	BUILD_DIR := $(BUILD_DIR)-cpp
+else
+	CFLAGS += -std=c99
+endif
+
+# Architecture configuration.
+ifeq ($(ARCH),32)
+	CFLAGS += -m32
+	WREN := $(WREN)-32
+	BUILD_DIR := $(BUILD_DIR)-32
+endif
+
+ifeq ($(ARCH),64)
+	CFLAGS += -m64
+	WREN := $(WREN)-64
+	BUILD_DIR := $(BUILD_DIR)-64
+endif
+
+# Don't add -fPIC on Windows since it generates a warning which gets promoted
+# to an error by -Werror.
+OS := $(lastword $(subst -, ,$(shell $(CC) -dumpmachine)))
+ifeq      ($(OS),mingw32)
+else ifeq ($(OS),cygwin)
+	# Do nothing.
+else
+	CFLAGS += -fPIC
+endif
+
+# Clang on Mac OS X has different flags and a different extension to build a
+# shared library.
+ifneq (,$(findstring darwin,$(OS)))
+	SHARED_EXT := dylib
+else
+	SHARED_LIB_FLAGS := -Wl,-soname,$@.so
+	SHARED_EXT := so
+endif
+
+# TODO: Simplify this if we mode main.c to a different directory.
+OBJECTS := $(addprefix $(BUILD_DIR)/, $(notdir $(SOURCES:.c=.o)))
+# Don't include main.c in the libraries.
+LIB_OBJECTS := $(subst $(BUILD_DIR)/main.o,,$(OBJECTS))
+
+# Targets ---------------------------------------------------------------------
+
+all: prep bin/$(WREN) lib/lib$(WREN).a lib/lib$(WREN).$(SHARED_EXT)
+
+prep:
+	@mkdir -p bin lib $(BUILD_DIR)
+
+# Command-line interpreter.
+bin/$(WREN): $(OBJECTS)
+	$(CC) $(CFLAGS) -Iinclude -o $@ $^ -lm
+
+# Static library.
+lib/lib$(WREN).a: $(LIB_OBJECTS)
+	$(AR) rcu $@ $^
+
+# Shared library.
+lib/lib$(WREN).$(SHARED_EXT): $(LIB_OBJECTS)
+	$(CC) $(CFLAGS) -shared $(SHARED_LIB_FLAGS) -o $@ $^
+
+# Object files.
+$(BUILD_DIR)/%.o: src/%.c $(HEADERS)
+	$(CC) -c $(CFLAGS) -Iinclude -o $@ $(FILE_FLAG) $<
diff --git a/src/main.c b/src/main.c
index 4f6e5de6..db80902e 100644
--- a/src/main.c
+++ b/src/main.c
@@ -56,7 +56,7 @@ static char* readModule(WrenVM* vm, const char* module)
   size_t rootLength = strlen(rootDirectory);
   size_t moduleLength = strlen(module);
   size_t pathLength = rootLength + moduleLength + 5;
-  char* path = malloc(pathLength + 1);
+  char* path = (char*)malloc(pathLength + 1);
   memcpy(path, rootDirectory, rootLength);
   memcpy(path + rootLength, module, moduleLength);
   memcpy(path + rootLength + moduleLength, ".wren", 5);
@@ -107,7 +107,7 @@ static int runFile(WrenVM* vm, const char* path)
   // Use the directory where the file is as the root to resolve imports
   // relative to.
   char* lastSlash = strrchr(path, '/');
-  rootDirectory = malloc(lastSlash - path + 2);
+  rootDirectory = (char*)malloc(lastSlash - path + 2);
   memcpy(rootDirectory, path, lastSlash - path + 1);
   rootDirectory[lastSlash - path + 1] = '\0';
 
diff --git a/src/wren_vm.c b/src/wren_vm.c
index 8959650b..7605f391 100644
--- a/src/wren_vm.c
+++ b/src/wren_vm.c
@@ -1208,7 +1208,7 @@ WrenInterpretResult wrenInterpret(WrenVM* vm, const char* sourcePath,
                                   const char* source)
 {
   if (strlen(sourcePath) == 0) return loadIntoCore(vm, source);
-  
+
   // TODO: Better module name.
   Value name = wrenNewString(vm, "main", 4);
   wrenPushRoot(vm, AS_OBJ(name));
@@ -1345,7 +1345,7 @@ static void defineMethod(WrenVM* vm, const char* className,
 
   // TODO: Need to be able to define methods in classes outside the core
   // module.
-  
+
   // Find or create the class to bind the method to.
   ObjModule* coreModule = getCoreModule(vm);
   int classSymbol = wrenSymbolTableFind(&coreModule->variableNames,
@@ -1460,7 +1460,7 @@ void wrenReturnString(WrenVM* vm, const char* text, int length)
 {
   ASSERT(vm->foreignCallSlot != NULL, "Must be in foreign call.");
   ASSERT(text != NULL, "String cannot be NULL.");
-  
+
   size_t size = length;
   if (length == -1) size = strlen(text);