diff --git a/clibs/compile.c b/clibs/compile.c
index 8261e781..e10544d9 100644
--- a/clibs/compile.c
+++ b/clibs/compile.c
@@ -770,8 +770,8 @@ static Slot compile_function(GstCompiler *c, FormOptions opts, GstValue *form) {
         uint16_t literalIndex;
         GstFuncDef *def = compiler_gen_funcdef(c, buffer->count - sizeBefore, params->count);
         /* Add this FuncDef as a literal in the outer scope */
-        newVal.type = GST_NIL;
-        newVal.data.pointer = def;
+        newVal.type = GST_FUNCDEF;
+        newVal.data.def = def;
         literalIndex = compiler_add_literal(c, scope, newVal);
         gst_buffer_push_u16(c->vm, buffer, GST_OP_CLN);
         gst_buffer_push_u16(c->vm, buffer, ret.index);
diff --git a/core/deserialize.c b/core/deserialize.c
new file mode 100644
index 00000000..afe55992
--- /dev/null
+++ b/core/deserialize.c
@@ -0,0 +1,380 @@
+#include <gst/datatypes.h>
+#include <gst/vm.h>
+#include <gst/values.h>
+#include <gst/ds.h>
+#include <gst/util.h>
+
+/**
+ * Data format
+ * State is encoded as a string of unsigned bytes.
+ *
+ * Types:
+ *
+ * Byte 0 to 200: small integer byte - 100
+ * Byte 201: Nil
+ * Byte 202: True
+ * Byte 203: False
+ * Byte 204: Number  - double format
+ * Byte 205: String  - [u32 length]*[u8... characters]
+ * Byte 206: Buffer  - [u32 length]*[u8... characters]
+ * Byte 207: Array   - [u32 length]*[value... elements]
+ * Byte 208: Tuple   - [u32 length]*[value... elements]
+ * Byte 209: Thread  - [u8 state][u32 frames]*[[value callee][value env]
+ *  [u32 pcoffset][u32 erroffset][u16 ret][u16 errloc][u16 size]*[value ...stack]
+ * Byte 210: Object  - [value meta][u32 length]*2*[value... kvs]
+ * Byte 211: FuncDef - [u32 locals][u32 arity][u32 flags][u32 literallen]*[value...
+ *  literals][u32 bytecodelen]*[u16... bytecode]
+ * Byte 212: FunEnv  - [value thread][u32 length]*[value ...upvalues]
+ *  (upvalues is not read if thread is a thread object)
+ * Byte 213: Func    - [value parent][value def][value env]
+ *  (nil values indicate empty)
+ * Byte 214: LUdata  - [value meta][u32 length]*[u8... bytes]
+ * Byte 215: CFunc   - [u32 length]*[u8... idstring]
+ * Byte 216: Ref     - [u32 id]
+ */
+
+/* Error at buffer end */
+static const char UEB[] = "unexpected end of buffer";
+
+/* Read 4 bytes as an unsigned integer */
+static uint32_t bytes2u32(uint8_t bytes[4]) {
+    union {
+        uint8_t bytes[4];
+        uint32_t u32;
+    } u;
+    u.bytes = bytes;
+    return u.u32;
+}
+
+/* Read 2 bytes as unsigned short */
+static uint16_t bytes2u16(uint8_t bytes[2]) {
+    union {
+        uint8_t bytes[2];
+        uint16_t u16;
+    } u;
+    u.bytes = bytes;
+    return u.u16;
+}
+
+/* Read 8 bytes as a double */
+static uint32_t bytes2dbl(uint8_t bytes[8]) {
+    union {
+        uint8_t bytes[8];
+        double dbl;
+    } u;
+    u.bytes = bytes;
+    return u.dbl;
+}
+
+/* Read a string and turn it into a gst value */
+static GstValue gst_deserialize_impl(
+        Gst *vm, 
+        uint8_t *data,
+        uint8_t *end,
+        uint8_t **newData,
+        GstArray *visited) {
+
+    GstValue ret;
+    ret.type = GST_NIL;
+    GstValue *buffer;
+    uint32_t length, i;
+
+    /* Handle errors as needed */
+#define deser_error(e) (exit(-1), NULL)
+
+    /* Assertions */
+#define deser_assert(c, e) do{if(!(c))deser_error(e);}while(0)
+
+    /* Assert enough buffer */
+#define deser_datacheck(len) (end - data < (len) ? deser_error(UEB) : data)
+
+    /* Check for enough space to read uint32_t */
+#define read_u32() (deser_datacheck(4), bytes2u32(data))
+
+    /* Check for enough space to read uint16_t */
+#define read_u16() (deser_datacheck(2), bytes2u16(data))
+
+    /* Check for enough space to read uint32_t */
+#define read_dbl() (deser_datacheck(8), bytes2dbl(data))
+
+    /* Check enough buffer left to read one byte */
+    if (data >= end) deser_error(UEB);
+
+    /* Small integer */
+    if (*data < 201) {
+        ret.type = GST_NUMBER;
+        ret.data.number = *data - 100; 
+        newData = data + 1;
+        return ret;
+    } 
+
+    /* Main switch for types */
+    switch (*data++) {
+
+        case 201: /* Nil */
+            ret.type = GST_NIL;
+            *newData = data;
+            return ret;
+
+        case 202: /* True */
+            ret.type = GST_BOOLEAN;
+            ret.data.boolean = 1;
+            *newData = data;
+            return ret;
+
+        case 203: /* False */
+            ret.type = GST_BOOLEAN;
+            ret.data.boolean = 0;
+            *newData = data;
+            return ret;
+
+        case 204: /* Long number (double) */
+            ret.type = GST_NUMBER; 
+            ret.data.number = read_dbl();
+            *newData = data + 8;
+            return ret;
+
+        case 205: /* String */
+            ret.type = GST_STRING;
+            length = read_u32(); data += 4;
+            data = deser_datacheck(length);
+            ret.data.string = 
+                gst_alloc(vm, 2 * sizeof(uint32_t) + length + 1) + 2 * sizeof(uint32_t);
+            gst_string_length(ret.data.string) = length;
+            gst_string_hash(ret.data.string) = 0;
+            gst_memcpy(ret.data.string, data, length);
+            ret.data.string[length] = 0;
+            *newData = data + length;
+            gst_array_push(vm, visited, ret);
+            return ret;
+
+        case 206: /* Buffer */
+            ret.type = GST_BUFFER;
+            length = read_u32(); data += 4;
+            data = deser_datacheck(length);
+            ret.data.buffer = gst_alloc(vm, sizeof(GstBuffer));
+            ret.data.buffer->data = gst_alloc(vm, length);
+            gst_memcpy(ret.data.string, data, length;
+            ret.data.buffer->count = length;
+            ret.data.buffer->capacity = length;
+            *newData = data + length;
+            gst_array_push(vm, visited, ret);
+            return ret;
+
+        case 207: /* Array */
+            ret.type = GST_ARRAY;
+            length = read_u32(); data += 4;
+            buffer = gst_alloc(vm, length * sizeof(GstValue));
+            for (i = 0; i < length; ++i)
+                buffer[i] = gst_deserialize_impl(vm, data, end, &data, visited);
+            ret.data.array = gst_alloc(vm, sizeof(GstArray));
+            ret.data.array->data = buffer;
+            ret.data.array->count = length;
+            ret.data.array->capacity = length;
+            *newData = data;
+            gst_array_push(vm, visited, ret);
+            return ret;
+
+        case 208: /* Tuple */
+            ret.type = GST_TUPLE;
+            length = read_u32(); data += 4;
+            buffer = gst_alloc(vm, length * sizeof(GstValue) + 2 * sizeof(uint32_t))
+                + 2 * sizeof(uint32_t);
+            for (i = 0; i < length; ++i)
+                buffer[i] = gst_deserialize_impl(vm, data, end, &data, visited);
+            gst_tuple_hash(buffer) = 0;
+            gst_tuple_length(buffer) = length;
+            ret.data.tuple = buffer;
+            *newData = data;
+            gst_array_push(vm, visited, ret);
+            return ret;
+
+        case 209: /* Thread */
+            {
+                GstValue nil;
+                GstThread *t;
+                GstValue *stack;
+                uint16_t prevsize = 0;
+                uint8 statusbyte;
+                nil.type = GST_NIL;
+                t = gst_thread(vm, 64, nil);
+                ret.type = GST_THREAD;
+                ret.data.thread = t;
+                deser_assert(data < end, UEB);
+                statusbyte = *data++;
+                length = read_u32(); data += 4;
+                /* Check for empty thread */
+                if (length == 0) {
+                    *newData = data;
+                    return ret;
+                } 
+                /* Set status */
+                if (statusbyte == 0) t->status = GST_THREAD_PENDING;
+                else if (statusbyte == 1) t->status = GST_THREAD_ALIVE;
+                else t->status = GST_THREAD_DEAD;
+                /* Add frames */
+                for (i = 0; i < length; ++i) {
+                    GstValue callee, env;
+                    uint32_t pcoffset, erroffset;
+                    uint16_t ret, errloc, size, j;
+                    /* Create a new frame */
+                    if (i > 0)
+                        gst_thread_beginframe(vm, t, nil, 0);
+                    /* Read the stack */
+                    callee = gst_deserialize_impl(vm, data, end, &data, visited);
+                    env = gst_deserialize_impl(vm, data, end, &data, visited);
+                    pcoffset = read_u32(); data += 4;
+                    erroffset = read_u32(); data += 4;
+                    ret = read_u16(); data += 2;
+                    errloc = read_u16(); data += 2;
+                    size = read_u16(); data += 2;
+                    /* Set up the stack */
+                    stack = gst_thread_stack(t);
+                    if (callee.type = GST_FUNCTION) {
+                        gst_frame_pc(stack) = callee.data.function->def->byteCode + pcoffset;
+                        gst_frame_errjmp(stack) = callee.data.function->def->byteCode + erroffset;
+                        if (env.type == GST_FUNCENV)
+                            gst_frame_env(stack) = env.data.env;
+                    }
+                    gst_frame_ret(stack) = ret;
+                    gst_frame_errloc(stack) = errloc;
+                    gst_frame_size(stack) = size;
+                    gst_frame_prevsize(stack) = prevsize;
+                    prevsize = size;
+                    /* Push stack args */
+                    for (j = 0; j < size; ++j) {
+                        GstValue temp = gst_deserialize_impl(vm, data, end, &data, visited);
+                        gst_thread_push(vm, t, temp);
+                    }
+                }
+                *newData = data;
+            }
+            return ret;
+
+        case 210: /* Object */
+            {
+                GstValue meta;
+                ret.type = GST_OBJECT;
+                ret.data.object = gst_object(vm, 10);
+                meta = gst_deserialize_impl(vm, data, end, &data, visited);
+                length = read_u32(); data += 4;
+                for (i = 0; i < length; i += 2) {
+                    GstValue key, value;
+                    key = gst_deserialize_impl(vm, data, end, &data, visited);
+                    value = gst_deserialize_impl(vm, data, end, &data, visited);
+                    gst_object_put(vm, ret.data.object, key, value);
+                }
+                if (meta.type == GST_OBJECT) {
+                    ret.data.object->meta = meta.data.object; 
+                }
+                *newData = data;
+                gst_array_push(vm, visited, ret);
+            }
+            return ret;
+
+        case 211: /* Funcdef */
+            {
+                GstFuncDef *def;
+                uint32_t locals, arity, literalsLen, byteCodeLen, flags;
+                locals = read_u32(); data += 4;
+                arity = read_u32(); data += 4;
+                flags = read_u32(); data += 4;
+                literalsLen = read_u32(); data += 4;
+                def = gst_alloc(vm, sizeof(GstFuncDef));
+                ret.type = GST_FUNCDEF;
+                ret.data.def = def;
+                def->locals = locals;
+                def->arity = arity;
+                def->flags = flags;
+                def->literalsLen = literalsLen;
+                if (literalsLen > 0) {
+                    def->literals = gst_alloc(vm, literalsLen * sizeof(GstValue));
+                }
+                for (i = 0; i < literalsLen; ++i) {
+                    def->literals[i] = gst_deserialize_impl(vm, data, end, &data, visited);
+                }
+                byteCodeLen = read_u32(); data += 4;
+                deser_datacheck(byteCodeLen);
+                def->byteCode = vm_alloc(vm, byteCodeLen * sizeof(uint16_t));
+                def->byteCodeLen = byteCodeLen;
+                for (i = 0; i < byteCodeLen; ++i) {
+                    def->byteCode[i] = read_u16();
+                    data += 2;    
+                }
+                *newData = data;
+                gst_array_push(vm, visited, ret);
+            }
+            return ret;
+
+        case 212: /* Funcenv */
+            {
+                GstValue thread = gst_deserialize_impl(vm, deata, &data, visited);
+                length = read_u32(); data += 4;
+                ret.type = GST_FUNCENV;
+                ret.data.env = gst_alloc(vm, sizeof(GstFuncEnv));
+                ret.data.env->stackOffset = length;
+                if (thread.type == GST_THREAD) {
+                    ret.data.env->thread = thread.data.thread;
+                } else {
+                    ret.data.env->thread = NULL;
+                    ret.data.env->values = vm_alloc(vm, sizeof(GstValue) * length);
+                    for (i = 0; i < length; ++i) {
+                        GstValue item = gst_deserialize_impl(vm, data, end, &data, visited);
+                        ret.data.env->values[i] = item;
+                    }
+                }
+                *newData = data;
+                gst_array_push(vm, visited, ret);
+            }
+            return ret;
+
+        case 213: /* Function */
+            {
+                GstValue parent, def, env;
+                parent = gst_deserialize_impl(vm, data, end, &data, visited);
+                def = gst_deserialize_impl(vm, data, end, &data, visited);
+                env = gst_deserialize_impl(vm, data, end, &data, visited);
+                ret.type = GST_FUNCTION;
+                ret.data.function = gst_alloc(vm, sizeof(GstFunction));
+                if (parent->type == GST_NIL) {
+                    ret.data.function->parent = NULL;
+                } else if (parent->type == GST_FUNCTION) {
+                    ret.data.function->parent = parent.data.function;
+                } else {
+                    deser_error("expected function");
+                }
+                gst_assert(def->type == GST_FUNCDEF, "expected funcdef");
+                gst_assert(env->type == GST_FUNCENV, "expected funcenv");
+                ret.data.function->env = env.data.env;
+                ret.data.function->def = env.data.def;
+                *newData = data;
+                gst_array_push(vm, visited, ret);
+            }
+            return ret;
+
+        case 214: /* LUdata */
+            {
+                GstValue meta;
+                ret.type = GST_USERDATA;
+                meta = gst_deserialize_impl(vm, data, end, &data, visited);
+                deser_assert(meta.type == GST_OBJECT, "userdata requires valid meta");
+                length = read_u32(); data += 4;
+                data = deser_datacheck(length);
+                ret.data.pointer = gst_userdata(vm, length, meta.data.object);
+                gst_memcpy(ret.data.pointer, data, length);
+                *newData = data + length;
+                gst_array_push(vm, visited, ret);
+            }
+            return ret;
+
+        case 215: /* C function */
+
+            return ret;
+
+        case 216: /* Reference */
+            length = read_u32(); data += 4;
+            deser_assert(visited->count > length, "invalid reference");
+            *newData = data;
+            return visited->data[length];
+    }
+}
diff --git a/core/gc.c b/core/gc.c
index 6dd64bb4..23c35d9c 100644
--- a/core/gc.c
+++ b/core/gc.c
@@ -42,15 +42,8 @@ static void gst_mark_funcdef(Gst *vm, GstFuncDef *def) {
         if (def->literals) {
             count = def->literalsLen;
             gc_header(def->literals)->color = vm->black;
-            for (i = 0; i < count; ++i) {
-                /* If the literal is a NIL type, it actually
-                 * contains a FuncDef */
-                if (def->literals[i].type == GST_NIL) {
-                    gst_mark_funcdef(vm, (GstFuncDef *) def->literals[i].data.pointer);
-                } else {
-                    gst_mark(vm, def->literals + i);
-                }
-            }
+            for (i = 0; i < count; ++i)
+                gst_mark(vm, def->literals + i);
         }
     }
 }
@@ -167,6 +160,14 @@ void gst_mark(Gst *vm, GstValue *x) {
                 temp.data.object = userHeader->meta;
                 gst_mark(vm, &temp);
             }
+
+        case GST_FUNCENV:
+            gst_mark_funcenv(vm, x->data.env);
+            break;
+
+        case GST_FUNCDEF:
+            gst_mark_funcdef(vm, x->data.def);
+            break;
     }
 }
 
@@ -251,70 +252,3 @@ void gst_clear_memory(Gst *vm) {
     }
     vm->blocks = NULL;
 }
-
-/* Header for managed memory blocks */
-struct MMHeader {
-    struct MMHeader *next;
-    struct MMHeader *previous;
-};
-
-/* Initialize managed memory */
-void gst_mm_init(GstManagedMemory *mm) {
-    *mm = NULL;
-}
-
-/* Allocate some managed memory */
-void *gst_mm_alloc(GstManagedMemory *mm, uint32_t size) {
-    struct MMHeader *mem = gst_raw_alloc(size + sizeof(struct MMHeader));
-    if (mem == NULL)
-        return NULL;
-    mem->next = *mm;
-    mem->previous = NULL;
-    *mm = mem;
-    return mem + 1;
-}
-
-/* Intialize zeroed managed memory */
-void *gst_mm_zalloc(GstManagedMemory *mm, uint32_t size) {
-    struct MMHeader *mem = gst_raw_calloc(1, size + sizeof(struct MMHeader));
-    if (mem == NULL)
-        return NULL;
-    mem->next = *mm;
-    mem->previous = NULL;
-    *mm = mem;
-    return mem + 1;
-}
-
-/* Free a memory block used in managed memory */
-void gst_mm_free(GstManagedMemory *mm, void *block) {
-    struct MMHeader *mem = (struct MMHeader *)(((char *)block) - sizeof(struct MMHeader));
-    if (mem->previous != NULL) {
-        mem->previous->next = mem->next;
-    } else {
-        *mm = mem->next;
-    }
-    gst_raw_free(mem);
-}
-
-/* Free all memory in managed memory */
-void gst_mm_clear(GstManagedMemory *mm) {
-    struct MMHeader *block = (struct MMHeader *)(*mm);
-    struct MMHeader *next;
-    while (block != NULL) {
-        next = block->next;
-        free(block);
-        block = next;
-    };
-    *mm = NULL;
-}
-
-/* Analog to realloc */
-void *gst_mm_realloc(GstManagedMemory *mm, void *block, uint32_t nsize) {
-    struct MMHeader *mem = gst_raw_realloc(block, nsize + sizeof(struct MMHeader));
-    if (mem == NULL)
-        return NULL;
-    mem->next = *mm;
-    mem->previous = NULL;
-    *mm = mem;
-    return mem + 1;
-}
diff --git a/core/thread.c b/core/thread.c
index ab3fbe59..3e6d8a56 100644
--- a/core/thread.c
+++ b/core/thread.c
@@ -118,7 +118,7 @@ GstValue *gst_thread_expand_callable(Gst *vm, GstThread *thread, GstValue callee
                 continue;
         }
     }
-    /* Callables nested to deeply */
+    /* Callables nested too deeply */
     return NULL;
 }
 
diff --git a/core/value.c b/core/value.c
index a6a9c6c9..34c223b2 100644
--- a/core/value.c
+++ b/core/value.c
@@ -104,6 +104,10 @@ uint8_t *gst_to_string(Gst *vm, GstValue x) {
             return string_description(vm, "thread", 6, x.data.pointer);
         case GST_USERDATA:
             return string_description(vm, "userdata", 8, x.data.pointer);
+        case GST_FUNCENV:
+            return string_description(vm, "funcenv", 7, x.data.pointer);
+        case GST_FUNCDEF:
+            return string_description(vm, "funcdef", 7, x.data.pointer);
     }
     return NULL;
 }
diff --git a/core/vm.c b/core/vm.c
index 24894455..6c5f9882 100644
--- a/core/vm.c
+++ b/core/vm.c
@@ -221,10 +221,10 @@ static int gst_continue_size(Gst *vm, uint32_t stackBase) {
                 if (pc[2] > v1.data.function->def->literalsLen)
                     gst_error(vm, GST_NO_UPVALUE);
                 temp = v1.data.function->def->literals[pc[2]];
-                if (temp.type != GST_NIL)
+                if (temp.type != GST_FUNCDEF)
                     gst_error(vm, "cannot create closure");
                 fn = gst_alloc(vm, sizeof(GstFunction));
-                fn->def = (GstFuncDef *) temp.data.pointer;
+                fn->def = temp.data.def;
                 fn->parent = v1.data.function;
                 fn->env = gst_frame_env(stack);
                 temp.type = GST_FUNCTION;
@@ -394,6 +394,7 @@ static int gst_continue_size(Gst *vm, uint32_t stackBase) {
                     pc = temp.data.function->def->byteCode;
                 } else {
                     int status;
+                    gst_frame_pc(stack) = pc;
                     GST_STATE_WRITE();
                     vm->ret.type = GST_NIL;
                     status = temp.data.cfunction(vm);