diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index e5aa8cf..ac34f1f 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -18,3 +18,5 @@ set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${PROJECT_SOURCE_DIR}/../bin/std")
 file(GLOB_RECURSE STDLIB_IO_SOURCE_FILES io/*.c)
 add_library(io ${STDLIB_IO_SOURCE_FILES})
 
+file(GLOB_RECURSE STDLIB_MEM_SOURCE_FILES mem/*.c)
+add_library(mem ${STDLIB_MEM_SOURCE_FILES})
diff --git a/lib/def/def.h b/lib/def/api.h
similarity index 100%
rename from lib/def/def.h
rename to lib/def/api.h
diff --git a/lib/def/mod.gem b/lib/def/mod.gem
deleted file mode 100644
index 22bfd7f..0000000
--- a/lib/def/mod.gem
+++ /dev/null
@@ -1,34 +0,0 @@
-# Author: Sven Vogel
-# Edited: 25.05.2024
-# License: GPL-2.0
-
-# ,----------------------------------------.
-# |       Standard Type definitions        |
-# `----------------------------------------`
-
-# Unsigned integrals
-
-type unsgined half half int: u8
-type unsgined half int: u16
-type unsgined int: u32
-type unsgined double int: u64
-type unsgined double double int: u128
-
-# Signed integrals
-
-type signed u8: i8
-type signed u16: i16
-type signed u32: i32
-type signed u64: i64
-type signed u128: i128
-
-# IEEE-754 floating point
-
-type signed half float: f16
-type signed float: f32
-type signed double float: f64
-type signed double double float: f128
-
-# String constant
-
-type ref u8: str
diff --git a/lib/io/io.h b/lib/io/api.h
similarity index 94%
rename from lib/io/io.h
rename to lib/io/api.h
index 4e00856..c642185 100644
--- a/lib/io/io.h
+++ b/lib/io/api.h
@@ -2,7 +2,7 @@
 #ifndef GEMSTONE_STD_LIB_IO_H_
 #define GEMSTONE_STD_LIB_IO_H_
 
-#include <def/def.h>
+#include <def/api.h>
 
 typedef ptr handle;
 
diff --git a/lib/io/io.c b/lib/io/impl.c
similarity index 97%
rename from lib/io/io.c
rename to lib/io/impl.c
index f47dd6f..19fe716 100644
--- a/lib/io/io.c
+++ b/lib/io/impl.c
@@ -1,6 +1,5 @@
 
-#include <io/io.h>
-#include <stdio.h>
+#include <io/api.h>
 
 #if defined(_WIN32) || defined (_WIN64)
 
diff --git a/lib/mem.gem b/lib/mem.gem
new file mode 100644
index 0000000..faecbc4
--- /dev/null
+++ b/lib/mem.gem
@@ -0,0 +1,27 @@
+# Author: Sven Vogel
+# Edited: 25.05.2024
+# License: GPL-2.0
+
+# ,----------------------------------------.
+# |            Memory Management           |
+# `----------------------------------------`
+
+import "def.gem"
+
+# Allocate `len` bytes of heap memory
+# Returns a pointer to the memory as `ptr`
+fun heap_alloc(in u32: len)(out ref u8: ptr)
+
+# Rellocate `len` bytes of heap memory
+# Returns a pointer to the memory as `ptr`
+fun heap_realloc(in u32: len, in out ref u8: ptr)
+
+# Free a block of memory
+fun heap_free(in ref u8: ptr)
+
+# Copy `len` bytes from `dst` into `src`
+fun copy(in ref u8: dst, in ref u8: src, in u32 len)
+
+# Fill `len` bytes of `dst` with `byte`
+fun fill(in ref u8: dst, in u8: byte, in u32 len)
+
diff --git a/lib/mem/api.h b/lib/mem/api.h
new file mode 100644
index 0000000..8ca69c0
--- /dev/null
+++ b/lib/mem/api.h
@@ -0,0 +1,17 @@
+
+#ifndef GEMSTONE_STD_LIB_MEM_H_
+#define GEMSTONE_STD_LIB_MEM_H_
+
+#include <def/api.h>
+
+void heap_alloc(u32 len, u8** ptr);
+
+void heap_realloc(u32 len, u8** ptr);
+
+void heap_free(u8* ptr);
+
+void copy(u8* dst, u8* src, u32 len);
+
+void fill(u8* dst, u8 byte, u32 len);
+
+#endif // GEMSTONE_STD_LIB_MEM_H_
diff --git a/lib/mem/impl.c b/lib/mem/impl.c
new file mode 100644
index 0000000..95863ac
--- /dev/null
+++ b/lib/mem/impl.c
@@ -0,0 +1,51 @@
+
+#include <mem/api.h>
+
+#if defined(_WIN32) || defined (_WIN64)
+
+#include <Windows.h>
+
+#define HEAP_API_GLOBAL_FLAGS HEAP_ZERO_MEMORY | HEAP_GENERATE_EXCEPTIONS
+
+void heap_alloc(u32 len, u8** ptr) {
+    HANDLE heap = GetProcessHeap();
+    *ptr = HeapAlloc(heap, HEAP_API_GLOBAL_FLAGS, len);
+}
+
+void heap_realloc(u32 len, u8** ptr) {
+    HANDLE heap = GetProcessHeap();
+    *ptr = HeapReAlloc(heap, HEAP_API_GLOBAL_FLAGS, *ptr, len);
+}
+
+void heap_free(u8* ptr) {
+    HANDLE heap = GetProcessHeap();
+    HeapFree(heap, ptr);
+}
+
+#elif defined(unix) || defined(__unix) || defined(__unix__) || defined(__linux__)
+
+#include <malloc.h>
+
+void heap_alloc(u32 len, u8** ptr) {
+    *ptr = malloc(len);
+}
+
+void heap_realloc(u32 len, u8** ptr) {
+    *ptr = realloc(*ptr, len);
+}
+
+void heap_free(u8* ptr) {
+    free(ptr);
+}
+
+#endif
+
+#include <string.h>
+
+void copy(u8* dst, u8* src, u32 len) {
+    memcpy(dst, src, len);
+}
+
+void fill(u8* dst, u8 byte, u32 len) {
+    memset(dst, byte, len);
+}
\ No newline at end of file
diff --git a/lib/std.gem b/lib/std.gem
index 8f50d04..e135a13 100644
--- a/lib/std.gem
+++ b/lib/std.gem
@@ -9,4 +9,8 @@
 # standard type definitions
 import "def.gem"
 
+# I/O operations
+import "io.gem"
 
+# memory management
+import "mem.gem"