diff --git a/.gitignore b/.gitignore
index 5e644ff6..efd5fa98 100644
--- a/.gitignore
+++ b/.gitignore
@@ -26,9 +26,7 @@ APPS
 build
 
 main
-pocketpy.dSYM
-libpocketpy.dylib.dSYM/
-main.dSYM/
+*.dSYM
 
 docs/references.md
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0c17d50f..eb63418c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -69,7 +69,7 @@ else()
     target_link_libraries(main ${PROJECT_NAME})
 endif()
 
-# link math library
 if(UNIX)
     target_link_libraries(${PROJECT_NAME} m)
+    target_link_libraries(${PROJECT_NAME} dl)
 endif()
diff --git a/build.sh b/build.sh
index 9123bf92..b9c50eb4 100644
--- a/build.sh
+++ b/build.sh
@@ -19,7 +19,7 @@ SRC=$(find src/ -name "*.c")
 
 echo "> Compiling and linking source files... "
 
-clang -std=c11 -O2 -Wfatal-errors -Iinclude -DNDEBUG -o main src2/main.c $SRC -lm
+clang -std=c11 -O2 -Wfatal-errors -Iinclude -DNDEBUG -o main src2/main.c $SRC -lm -ldl
 
 if [ $? -eq 0 ]; then
     echo "Build completed. Type \"./main\" to enter REPL."
diff --git a/build_dll.sh b/build_dll.sh
new file mode 100644
index 00000000..772a07fe
--- /dev/null
+++ b/build_dll.sh
@@ -0,0 +1,6 @@
+set -e
+
+FLAGS="-std=c11 -Iinclude -O0 -Wfatal-errors -g -DDEBUG -DPK_ENABLE_OS=1"
+
+# link libpocketpy.dylib
+clang $FLAGS -shared -fPIC src2/hello.c -o libhello.dylib -L. -lpocketpy
diff --git a/build_g.sh b/build_g.sh
index 9909b282..b9570dd3 100644
--- a/build_g.sh
+++ b/build_g.sh
@@ -4,7 +4,7 @@ python prebuild.py
 
 SRC=$(find src/ -name "*.c")
 
-FLAGS="-std=c11 -lm -Iinclude -O0 -Wfatal-errors -g -DDEBUG -DPK_ENABLE_OS=1"
+FLAGS="-std=c11 -lm -ldl -Iinclude -O0 -Wfatal-errors -g -DDEBUG -DPK_ENABLE_OS=1"
 
 SANITIZE_FLAGS="-fsanitize=address,leak,undefined"
 
diff --git a/run_profile.sh b/run_profile.sh
index cc1528ea..28cc8c37 100644
--- a/run_profile.sh
+++ b/run_profile.sh
@@ -4,7 +4,7 @@ python prebuild.py
 
 SRC=$(find src/ -name "*.c")
 
-gcc -pg -Og -std=c11 -Wfatal-errors -o main $SRC src2/main.c -Iinclude -lm -DNDEBUG -flto
+gcc -pg -Og -std=c11 -Wfatal-errors -o main $SRC src2/main.c -Iinclude -lm -ldl -DNDEBUG -flto
 ./main benchmarks/fib.py
 gprof main gmon.out > gprof.txt
 rm gmon.out
diff --git a/run_tests.sh b/run_tests.sh
index 14915a2f..d827701b 100644
--- a/run_tests.sh
+++ b/run_tests.sh
@@ -4,7 +4,7 @@ python prebuild.py
 
 SRC=$(find src/ -name "*.c")
 
-clang -std=c11 --coverage -O1 -Wfatal-errors -o main src2/main.c $SRC -Iinclude -DPK_ENABLE_OS=1 -DPK_ENABLE_PROFILER=1 -lm -DNDEBUG
+clang -std=c11 --coverage -O1 -Wfatal-errors -o main src2/main.c $SRC -Iinclude -DPK_ENABLE_OS=1 -DPK_ENABLE_PROFILER=1 -lm -ldl -DNDEBUG
 
 python scripts/run_tests.py
 
diff --git a/src/interpreter/dll.c b/src/interpreter/dll.c
new file mode 100644
index 00000000..c60b8ec2
--- /dev/null
+++ b/src/interpreter/dll.c
@@ -0,0 +1,37 @@
+#include "pocketpy/pocketpy.h"
+
+#if PK_IS_DESKTOP_PLATFORM
+
+#ifdef _WIN32
+void* LoadLibraryA(const char*);
+void* GetProcAddress(void*, const char*);
+#else
+#include <dlfcn.h>
+#endif
+
+typedef bool (*py_module_initialize_t)() PY_RAISE PY_RETURN;
+
+int load_module_from_dll_desktop_only(const char* path) PY_RAISE PY_RETURN {
+    const char* f_init_name = "py_module_initialize";
+#ifdef _WIN32
+    void* dll = LoadLibraryA(path);
+    if(dll == NULL) return 0;
+    py_module_initialize_t f_init = (py_module_initialize_t)GetProcAddress(dll, f_init_name);
+#else
+    void* dll = dlopen(path, RTLD_LAZY);
+    if(dll == NULL) return 0;
+    py_module_initialize_t f_init = (py_module_initialize_t)dlsym(dll, f_init_name);
+#endif
+    if(f_init == NULL) return 0;
+    bool success = f_init();
+    if(!success) return -1;
+    return 1;
+}
+
+#else
+
+int load_module_from_dll_desktop_only(const char* path) PY_RAISE PY_RETURN {
+    return 0;
+}
+
+#endif
\ No newline at end of file
diff --git a/src/public/internal.c b/src/public/internal.c
index c1f8dcd4..fe7ab656 100644
--- a/src/public/internal.c
+++ b/src/public/internal.c
@@ -20,6 +20,10 @@ static VM pk_default_vm;
 static VM* pk_all_vm[16];
 
 void py_initialize() {
+    if(pk_current_vm){
+        c11__abort("py_initialize() can only be called once!");
+    }
+
     MemoryPools__initialize();
     py_Name__initialize();
 
diff --git a/src/public/modules.c b/src/public/modules.c
index df1a928a..6be8c503 100644
--- a/src/public/modules.c
+++ b/src/public/modules.c
@@ -63,9 +63,9 @@ py_Ref py_newmodule(const char* path) {
     return py_getmodule(path);
 }
 
-int py_import(const char* path_cstr) {
-    // printf("importing %s\n", path_cstr);
+int load_module_from_dll_desktop_only(const char* path) PY_RAISE PY_RETURN;
 
+int py_import(const char* path_cstr) {
     VM* vm = pk_current_vm;
     c11_sv path = {path_cstr, strlen(path_cstr)};
     if(path.size == 0) return ValueError("empty module name");
@@ -142,7 +142,8 @@ int py_import(const char* path_cstr) {
 
     c11_string__delete(filename);
     c11_string__delete(slashed_path);
-    return 0;
+    // not found
+    return load_module_from_dll_desktop_only(path_cstr);
 
 __SUCCESS:
     do {
diff --git a/src2/hello.c b/src2/hello.c
new file mode 100644
index 00000000..92520fdb
--- /dev/null
+++ b/src2/hello.c
@@ -0,0 +1,15 @@
+#include "pocketpy.h"
+
+static bool hello_add(int argc, py_Ref argv){
+    PY_CHECK_ARGC(2);
+    return py_binaryadd(py_arg(0), py_arg(1));
+}
+
+bool py_module_initialize(){
+    py_GlobalRef mod = py_newmodule("hello");
+
+    py_bindfunc(mod, "add", hello_add);
+
+    py_assign(py_retval(), mod);
+    return true;
+}
\ No newline at end of file