diff --git a/emk_project.py b/emk_project.py
new file mode 100644
index 0000000..be83606
--- /dev/null
+++ b/emk_project.py
@@ -0,0 +1,90 @@
+import os
+
+c, link = emk.module("c", "link")
+
+default_compile_flags = ["-fvisibility=hidden", "-Wall", "-Wextra", "-Wshadow", "-Werror", "-Wno-missing-field-initializers", "-Wno-unused-parameter", \
+    "-Wno-comment", "-Wno-unused", "-Wno-unknown-pragmas"]
+default_link_flags = []
+opt_flags = {"dbg":[], "std":["-O2"], "max":["-O3"], "small":["-Os"]}
+opt_link_flags = {"dbg":[], "std":[], "max":[], "small":[]}
+c_flags = ["-std=gnu11"]
+cxx_flags = ["-std=gnu++11", "-Wno-reorder", "-fno-rtti", "-fno-exceptions"]
+c_link_flags = []
+cxx_link_flags = ["-fno-rtti", "-fno-exceptions"]
+
+def setup_build_dir():
+    build_arch = None
+    if "arch" in emk.options:
+        build_arch = emk.options["arch"]
+    elif not emk.cleaning:
+        build_arch = "osx"
+    emk.options["arch"] = build_arch
+
+    opt_level = None
+    if "opt" in emk.options:
+        level = emk.options["opt"]
+        if level in opt_flags:
+            opt_level = level
+        else:
+            emk.log.warning("Unknown optimization level '%s'" % (level))
+    elif not emk.cleaning:
+        opt_level = "dbg"
+    emk.options["opt"] = opt_level
+
+    dirs = ["__build__"]
+    if build_arch:
+        dirs.append(build_arch)
+    if opt_level:
+        dirs.append(opt_level)
+    emk.build_dir = os.path.join(*dirs)
+
+def setup_osx():
+    global c
+    global link
+
+    flags = [("-arch", "x86_64"), "-fno-common", "-Wnewline-eof", "-mmacosx-version-min=10.7", "-D__DARWIN_UNIX03=0"]
+    c.flags.extend(flags)
+    c.cxx.flags += ["-stdlib=libc++"]
+    link.cxx.flags += ["-stdlib=libc++"]
+
+    link_flags = [("-arch", "x86_64"), "-mmacosx-version-min=10.7"]
+    link.local_flags.extend(link_flags)
+
+    dylib_flags = [("-current_version", "1.0"), ("-compatibility_version", "1.0")]
+    link.local_libflags.extend(dylib_flags)
+
+def setup_avr():
+    global c
+    global link
+
+    c.compiler = c.GccCompiler("/Projects/avr-tools/bin/avr-")
+    c.flags += ["-mmcu=atmega256rfr2", "-ffunction-sections", "-fdata-sections"]
+    link.linker = link.GccLinker("/Projects/avr-tools/bin/avr-")
+    link.flags += ["-mmcu=atmega256rfr2", "-mrelax", "-Wl,--gc-sections"]
+    link.strip = True
+
+setup_build_dir()
+
+setup_funcs = {"osx":setup_osx, "avr":setup_avr}
+
+if not emk.cleaning:
+    build_arch = emk.options["arch"]
+    opt_level = emk.options["opt"]
+
+    c.flags.extend(default_compile_flags)
+    c.flags.extend(opt_flags[opt_level])
+    c.c.flags.extend(c_flags)
+    c.cxx.flags.extend(cxx_flags)
+    link.local_flags.extend(default_link_flags)
+    link.local_flags.extend(opt_link_flags[opt_level])
+    link.c.local_flags.extend(c_link_flags)
+    link.cxx.local_flags.extend(cxx_link_flags)
+
+    c.include_dirs.append("$:proj:$")
+
+    if build_arch in setup_funcs:
+        setup_funcs[build_arch]()
+    else:
+        raise emk.BuildError("Unknown target arch '%s'" % (build_arch))
+
+    c.defines["TARGET_ARCH_" + build_arch.upper()] = 1
diff --git a/emk_rules.py b/emk_rules.py
index f1b9fb6..a785fef 100644
--- a/emk_rules.py
+++ b/emk_rules.py
@@ -1,2 +1 @@
 c, link = emk.module("c", "link")
-c.flags += ["-O3", "-Wall", "-Wextra", "-Werror", "-Wno-unused-parameter", "-Wno-unused-variable", "-Wno-unused-function"]