diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ca87aeb..927a7ea 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,10 +8,8 @@ on:
   schedule:
     - cron: "0 0 * * *"
 
-env:
-  TIMEOUT_MINUTES: 15
 jobs:
-  build_and_test:
+  linux_build_and_test:
     runs-on: ubuntu-24.04
     timeout-minutes: 15
     steps:
@@ -19,5 +17,13 @@ jobs:
         uses: actions/checkout@v4
       - name: Build and test
         run: |
-          set -ex
+          ./run_tests.sh
+  macos_build_and_test:
+    runs-on: macos-latest
+    timeout-minutes: 15
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Build and test
+        run: |
           ./run_tests.sh
diff --git a/bootstrap/main.cpp b/bootstrap/main.cpp
index 0143ef3..57224aa 100644
--- a/bootstrap/main.cpp
+++ b/bootstrap/main.cpp
@@ -81,6 +81,19 @@ forceinline fn u8 mem_equal_range(T* a, T* b, u64 count)
     return memcmp(a, b, count * sizeof(T)) == 0;
 }
 
+fn u8 memeq(u8* a, u8* b, u64 size)
+{
+    for (u64 i = 0; i < size; i += 1)
+    {
+        if (a[i] != b[i])
+        {
+            return 0;
+        }
+    }
+
+    return 1;
+}
+
 template<typename T>
 struct Slice
 {
@@ -241,6 +254,7 @@ struct StaticList
 //     return (Hash)result;
 // }
 
+#ifdef __linux__
 // fn forceinline long syscall0(long n)
 // {
 // 	unsigned long ret;
@@ -301,18 +315,6 @@ fn forceinline long syscall6(long n, long a1, long a2, long a3, long a4, long a5
 	return ret;
 }
 
-fn u8 memeq(u8* a, u8* b, u64 size)
-{
-    for (u64 i = 0; i < size; i += 1)
-    {
-        if (a[i] != b[i])
-        {
-            return 0;
-        }
-    }
-
-    return 1;
-}
 
 enum class SyscallX86_64 : u64 {
     read = 0,
@@ -685,40 +687,69 @@ enum class SyscallX86_64 : u64 {
     futex_requeue = 456,
 };
 
-fn void* syscall_mmap(void* address, size_t length, int protection_flags, int map_flags, int fd, __off_t offset)
+#endif
+
+fn void* syscall_mmap(void* address, size_t length, int protection_flags, int map_flags, int fd, signed long offset)
 {
+#ifdef __linux__
     return (void*) syscall6(static_cast<long>(SyscallX86_64::mmap), (unsigned long)address, length, protection_flags, map_flags, fd, offset);
+#else
+    return mmap(address, length, protection_flags, map_flags, fd, offset);
+#endif
 }
 
 fn int syscall_mprotect(void *address, size_t length, int protection_flags)
 {
+#ifdef __linux__
     return syscall3(static_cast<long>(SyscallX86_64::mprotect), (unsigned long)address, length, protection_flags);
+#else
+    return mprotect(address, length, protection_flags);
+#endif
 }
 
 fn int syscall_open(const char *file_path, int flags, int mode)
 {
+#ifdef __linux__
     return syscall3(static_cast<long>(SyscallX86_64::open), (unsigned long)file_path, flags, mode);
+#else
+    return open(file_path, flags, mode);
+#endif
 }
 
 fn int syscall_fstat(int fd, struct stat *buffer)
 {
+#ifdef __linux__
     return syscall2(static_cast<long>(SyscallX86_64::fstat), fd, (unsigned long)buffer);
+#else
+    return fstat(fd, buffer);
+#endif
 }
 
 fn ssize_t syscall_read(int fd, void* buffer, size_t bytes)
 {
+#ifdef __linux__
     return syscall3(static_cast<long>(SyscallX86_64::read), fd, (unsigned long)buffer, bytes);
+#else
+    return read(fd, buffer, bytes);
+#endif
 }
 
 fn ssize_t syscall_write(int fd, const void *buffer, size_t bytes)
 {
+#ifdef __linux__
     return syscall3(static_cast<long>(SyscallX86_64::write), fd, (unsigned long)buffer, bytes);
+#else
+    return write(fd, buffer, bytes);
+#endif
 }
 
 [[noreturn]] [[gnu::cold]] fn void syscall_exit(int status)
 {
+#ifdef __linux__
     (void)syscall1(231, status);
-    trap();
+#else
+    _exit(status);
+#endif
 }
 
 [[noreturn]] [[gnu::cold]] fn void fail()
@@ -3779,7 +3810,11 @@ String test_file_paths[] = {
     strlit("tests/simple_variable_declaration/main.nat"),
 };
 
+#ifdef __linux__
 extern "C" void entry_point()
+#else
+int main()
+#endif
 {
     instance.arena = Arena::init(Arena::default_size, Arena::minimum_granularity, KB(4));
 
diff --git a/compile.sh b/compile.sh
index c667d8b..367b704 100755
--- a/compile.sh
+++ b/compile.sh
@@ -1,27 +1,23 @@
 #!/bin/bash
-NEST_BUILD_DIR=build
-NEST_EXE_NAME=nest
-set -ex
-mkdir -p $NEST_BUILD_DIR
-time clang++ \
--o $NEST_BUILD_DIR/$NEST_EXE_NAME \
-bootstrap/main.cpp \
-bootstrap/entry.S \
-`# -Oz` \
-`# -march=native` \
-`# -Wl,-strip-all` \
--g \
--std=gnu++23 \
--Wall \
--Wextra \
--Wpedantic \
--Wno-nested-anon-types \
--pedantic \
--ffreestanding \
--nostdlib \
--static \
--fno-exceptions \
--fno-stack-protector \
--ferror-limit=1 \
-`#-ftime-report` \
--MJ $NEST_BUILD_DIR/compile_commands.json
+
+function compile()
+{
+    build_dir=$1
+    exe_name=$2
+    debug_info=$3
+    optimizations=$4
+
+    mkdir -p $build_dir
+
+    compile_command="time clang++ -o $build_dir/$exe_name $debug_info $optimizations -std=gnu++20 -Wall -Wextra -Wpedantic -Wno-nested-anon-types -pedantic -fno-exceptions -fno-stack-protector -ferror-limit=1 -MJ $build_dir/compile_commands.json"
+
+    case "$OSTYPE" in
+        darwin*)  ;;
+        linux*)   compile_command="$compile_command -ffreestanding -nostdlib -static bootstrap/entry.S" ;;
+        *)        echo "unknown: $OSTYPE" ;;
+    esac
+
+    compile_command="$compile_command bootstrap/main.cpp"
+    echo $compile_command
+    eval $compile_command
+}
diff --git a/debug.sh b/debug.sh
index 384a76f..49db25f 100755
--- a/debug.sh
+++ b/debug.sh
@@ -1,4 +1,16 @@
 #!/bin/bash
-set -ex
+
+set -e
+
 source ./compile.sh
-gf2 -ex r $NEST_BUILD_DIR/$NEST_EXE_NAME
+build_dir="build"
+exe_name="nest"
+exe_path=$build_dir/$exe_name
+
+compile $build_dir $exe_name "-g" "";
+
+case "$OSTYPE" in
+    darwin*)  lldb $exe_path ;; 
+    linux*)   gf2 -ex r $exe_path ;;
+    *)        echo "unknown: $OSTYPE" ;;
+esac
diff --git a/run_tests.sh b/run_tests.sh
index 041aa62..3e60860 100755
--- a/run_tests.sh
+++ b/run_tests.sh
@@ -1,4 +1,6 @@
 #!/bin/bash
+
 set -ex
 source ./compile.sh
+compile "build" "nest" "-g" "";
 build/nest