diff --git a/CMakeLists.txt b/CMakeLists.txt
index 60a68a3e..3ec4c45f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -58,6 +58,7 @@ src/core/corelib.c
 src/core/fiber.c
 src/core/gc.c
 src/core/io.c
+src/core/marsh.c
 src/core/math.c
 src/core/native.c
 src/core/os.c
diff --git a/src/compiler/stl.c b/src/compiler/stl.c
index 22ad97e4..f940af7e 100644
--- a/src/compiler/stl.c
+++ b/src/compiler/stl.c
@@ -136,6 +136,7 @@ DstTable *dst_stl_env(int flags) {
         dst_lib_compile(args);
         dst_lib_asm(args);
         dst_lib_string(args);
+        dst_lib_marsh(args);
     }
 
     /* Allow references to the environment */
diff --git a/src/core/fiber.c b/src/core/fiber.c
index 9a490841..74c4d551 100644
--- a/src/core/fiber.c
+++ b/src/core/fiber.c
@@ -24,6 +24,7 @@
 #include <dst/dstopcodes.h>
 #include <dst/dstcorelib.h>
 #include "fiber.h"
+#include "state.h"
 #include "gc.h"
 
 /* Initialize a new fiber */
@@ -217,7 +218,7 @@ void dst_fiber_funcframe_tail(DstFiber *fiber, DstFunction *func) {
 }
 
 /* Push a stack frame to a fiber for a c function */
-void dst_fiber_cframe(DstFiber *fiber) {
+void dst_fiber_cframe(DstFiber *fiber, DstCFunction cfun) {
     DstStackFrame *newframe;
 
     int32_t oldframe = fiber->frame;
@@ -235,7 +236,7 @@ void dst_fiber_cframe(DstFiber *fiber) {
 
     /* Set up the new frame */
     newframe->prevframe = oldframe;
-    newframe->pc = NULL;
+    newframe->pc = (uint32_t *) cfun;
     newframe->func = NULL;
     newframe->env = NULL;
     newframe->flags = 0;
@@ -347,12 +348,19 @@ static Dst doframe(DstStackFrame *frame) {
             dst_table_put(t, dst_csymbolv(":name"), dst_wrap_string(def->name));
         }
     } else {
+        DstCFunction cfun = (DstCFunction)(frame->pc);
+        if (cfun) {
+            Dst name = dst_table_get(dst_vm_registry, dst_wrap_cfunction(cfun));
+            if (!dst_checktype(name, DST_NIL)) {
+                dst_table_put(t, dst_csymbolv(":name"), name);
+            }
+        }
         dst_table_put(t, dst_csymbolv(":c"), dst_wrap_true());
     }
     if (frame->flags & DST_STACKFRAME_TAILCALL) {
         dst_table_put(t, dst_csymbolv(":tail"), dst_wrap_true());
     }
-    if (frame->pc) {
+    if (frame->func && frame->pc) {
         off = frame->pc - def->bytecode;
         dst_table_put(t, dst_csymbolv(":pc"), dst_wrap_integer(off));
         if (def->sourcemap) {
diff --git a/src/core/fiber.h b/src/core/fiber.h
index 000b02ee..dcc17105 100644
--- a/src/core/fiber.h
+++ b/src/core/fiber.h
@@ -42,7 +42,7 @@ void dst_fiber_push3(DstFiber *fiber, Dst x, Dst y, Dst z);
 void dst_fiber_pushn(DstFiber *fiber, const Dst *arr, int32_t n);
 void dst_fiber_funcframe(DstFiber *fiber, DstFunction *func);
 void dst_fiber_funcframe_tail(DstFiber *fiber, DstFunction *func);
-void dst_fiber_cframe(DstFiber *fiber);
+void dst_fiber_cframe(DstFiber *fiber, DstCFunction cfun);
 void dst_fiber_popframe(DstFiber *fiber);
 
 #endif
diff --git a/src/core/marsh.c b/src/core/marsh.c
new file mode 100644
index 00000000..536d1570
--- /dev/null
+++ b/src/core/marsh.c
@@ -0,0 +1,518 @@
+/*
+* Copyright (c) 2018 Calvin Rose
+*
+* Permission is hereby granted, free of charge, to any person obtaining a copy
+* of this software and associated documentation files (the "Software"), to
+* deal in the Software without restriction, including without limitation the
+* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+* sell copies of the Software, and to permit persons to whom the Software is
+* furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included in
+* all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+* IN THE SOFTWARE.
+*/
+
+#include <dst/dst.h>
+#include <setjmp.h>
+
+typedef struct {
+    jmp_buf err;
+    DstBuffer *buf;
+    DstTable seen;
+    int32_t nextid;
+} MarshalState;
+
+enum {
+    MR_OK,
+    MR_STACKOVERFLOW,
+    MR_NYI,
+    MR_OVERFLOW
+} MarshalResult;
+
+const char *mr_strings[] = {
+    "",
+    "stack overflow",
+    "type NYI",
+    "buffer overflow"
+};
+
+/* Lead bytes in marshaling protocol */
+enum {
+    LB_NIL = 200,
+    LB_FALSE,
+    LB_TRUE,
+    LB_FIBER,
+    LB_INTEGER,
+    LB_REAL,
+    LB_STRING,
+    LB_SYMBOL,
+    LB_ARRAY,
+    LB_TUPLE,
+    LB_TABLE,
+    LB_TABLE_PROTO,
+    LB_STRUCT,
+    LB_BUFFER,
+    LB_FUNCTION,
+    LB_CFUNCTION,
+    LB_ABSTRACT,
+    LB_REFERENCE
+} LeadBytes;
+
+/* Marshal an integer onto the buffer */
+static int pushint(DstBuffer *b, int32_t x) {
+    if (x >= 0 && x < 200) {
+        return dst_buffer_push_u8(b, x);
+    } else {
+        uint8_t intbuf[5];
+        intbuf[0] = LB_INTEGER;
+        intbuf[1] = x & 0xFF;
+        intbuf[2] = (x >> 8) & 0xFF;
+        intbuf[3] = (x >> 16) & 0xFF;
+        intbuf[4] = (x >> 24) & 0xFF;
+        return dst_buffer_push_bytes(b, intbuf, 5);
+    }
+}
+
+/* Forward declaration to enable mutual recursion. */
+static void marshal1(MarshalState *st, Dst x, int flags);
+
+/* Marshal a function environment */
+/*static void marshal1_env(MarshalState *st, DstFuncEnv *env, int flags) {*/
+
+/*}*/
+
+/* Marshal a function definition. */
+/*static void marshal1_def(MarshalState *st, DstFuncDef *def, int flags) {*/
+
+/*}*/
+
+/* The main body of the marshaling function. Is the main
+ * entry point for the mutually recursive functions. */
+static void marshal1(MarshalState *st, Dst x, int flags) {
+    DstBuffer *b = st->buf;
+    DstType type = dst_type(x);
+    if ((flags & 0xFFFF) > DST_RECURSION_GUARD) {
+        longjmp(st->err, MR_STACKOVERFLOW);
+    }
+
+    /* Check simple primitvies (non reference types, no benefit from memoization) */
+    switch (type) {
+        default:
+            break;
+        case DST_NIL:
+        case DST_FALSE:
+        case DST_TRUE:
+            {
+                if (dst_buffer_push_u8(b, 200 + type)) goto overflow;
+            }
+            return;
+        case DST_INTEGER:
+            {
+                if (pushint(b, dst_unwrap_integer(x))) goto overflow;
+            }
+            return;
+    }
+
+    /* Check reference */
+    {
+        Dst check = dst_table_get(&st->seen, x);
+        if (!dst_checktype(check, DST_NIL)) {
+            if (dst_buffer_push_u8(b, LB_REFERENCE)) goto overflow;
+            if (pushint(b, dst_unwrap_integer(check))) goto overflow;
+            return;
+        }
+    }
+
+#define MARK_SEEN() \
+    dst_table_put(&st->seen, x, dst_wrap_integer(st->nextid++))
+
+    /* Reference types */
+    switch (type) {
+        case DST_REAL:
+            {
+                union {
+                    double d;
+                    uint8_t bytes[8];
+                } u;
+                u.d = dst_unwrap_real(x);
+#ifdef DST_BIG_ENDIAN
+                /* Swap byte order */
+                uint8_t temp;
+                temp = u.bytes[7]; u.bytes[7] = u.bytes[0]; u.bytes[0] = temp;
+                temp = u.bytes[6]; u.bytes[6] = u.bytes[1]; u.bytes[1] = temp;
+                temp = u.bytes[5]; u.bytes[5] = u.bytes[2]; u.bytes[2] = temp;
+                temp = u.bytes[4]; u.bytes[4] = u.bytes[3]; u.bytes[3] = temp;
+#endif
+                if (dst_buffer_push_u8(b, LB_REAL)) goto overflow;
+                if (dst_buffer_push_bytes(b, u.bytes, 8)) goto overflow;
+                MARK_SEEN();
+            }
+            return;
+        case DST_STRING:
+        case DST_SYMBOL:
+            {
+                const uint8_t *str = dst_unwrap_string(x);
+                int32_t length = dst_string_length(str);
+                /* Record reference */
+                MARK_SEEN();
+                uint8_t lb = (type == DST_STRING) ? LB_STRING : LB_SYMBOL;
+                if (dst_buffer_push_u8(b, lb)) goto overflow;
+                if (pushint(b, length)) goto overflow;
+                if (dst_buffer_push_bytes(b, str, length)) goto overflow;
+            }
+            return;
+        case DST_BUFFER:
+            {
+                DstBuffer *buffer = dst_unwrap_buffer(x);
+                /* Record reference */
+                MARK_SEEN();
+                if (dst_buffer_push_u8(b, LB_BUFFER)) goto overflow;
+                if (pushint(b, buffer->count)) goto overflow;
+                if (dst_buffer_push_bytes(b, buffer->data, buffer->count)) goto overflow;
+            }
+            return;
+        case DST_ARRAY:
+            {
+                int32_t i;
+                DstArray *a = dst_unwrap_array(x);
+                MARK_SEEN();
+                if (dst_buffer_push_u8(b, LB_ARRAY)) goto overflow;
+                if (pushint(b, a->count)) goto overflow;
+                for (i = 0; i < a->count; i++) {
+                    marshal1(st, a->data[i], flags + 1);
+                }
+            }
+            return;
+        case DST_TUPLE:
+            {
+                int32_t i, count;
+                const Dst *tup = dst_unwrap_tuple(x);
+                count = dst_tuple_length(tup);
+                if (dst_buffer_push_u8(b, LB_TUPLE)) goto overflow;
+                if (pushint(b, count)) goto overflow;
+                for (i = 0; i < count; i++) {
+                    marshal1(st, tup[i], flags + 1);
+                }
+                /* Mark as seen AFTER marshaling */
+                MARK_SEEN();
+            }
+            return;
+        case DST_TABLE:
+            {
+                const DstKV *kv = NULL;
+                DstTable *t = dst_unwrap_table(x);
+                MARK_SEEN();
+                if (dst_buffer_push_u8(b, t->proto ? LB_TABLE_PROTO : LB_TABLE)) 
+                    goto overflow;
+                if (pushint(b, t->count)) goto overflow;
+                if (t->proto) {
+                    marshal1(st, dst_wrap_table(t->proto), flags + 1);
+                }
+                while ((kv = dst_table_next(t, kv))) {
+                    marshal1(st, kv->key, flags + 1);
+                    marshal1(st, kv->value, flags + 1);
+                }
+            }
+            return;
+        case DST_STRUCT:
+            {
+                int32_t count;
+                const DstKV *kv = NULL;
+                const DstKV *struct_ = dst_unwrap_struct(x);
+                count = dst_struct_length(struct_);
+                if (dst_buffer_push_u8(b, LB_STRUCT)) goto overflow;
+                if (pushint(b, count)) goto overflow;
+                while ((kv = dst_struct_next(struct_, kv))) {
+                    marshal1(st, kv->key, flags + 1);
+                    marshal1(st, kv->value, flags + 1);
+                }
+                /* Mark as seen AFTER marshaling */
+                MARK_SEEN();
+            }
+            return;
+        case DST_FIBER:
+        case DST_ABSTRACT:
+        case DST_FUNCTION:
+        case DST_CFUNCTION:
+        default:
+            goto nyi;
+    }
+
+#undef MARK_SEEN
+
+    /* Errors */
+
+nyi:
+    longjmp(st->err, MR_NYI);
+
+overflow:
+    longjmp(st->err, MR_OVERFLOW);
+}
+
+int dst_marshal(DstBuffer *buf, Dst x, int flags) {
+    int status;
+    MarshalState st; 
+    st.buf = buf;
+    st.nextid = 0;
+    dst_table_init(&st.seen, 0);
+    if (!(status = setjmp(st.err)))
+        marshal1(&st, x, flags);
+    dst_table_deinit(&st.seen);
+    return status;
+}
+
+typedef struct {
+    jmp_buf err;
+    DstArray lookup;
+    const uint8_t *end;
+} UnmarshalState;
+
+enum {
+    UMR_OK,
+    UMR_STACKOVERFLOW,
+    UMR_EOS,
+    UMR_UNKNOWN,
+    UMR_EXPECTED_INTEGER,
+    UMR_EXPECTED_TABLE,
+    UMR_INVALID_REFERENCE
+} UnmarshalResult;
+
+const char *umr_strings[] = {
+    "",
+    "stack overflow",
+    "unexpected end of source",
+    "unknown byte",
+    "expected integer",
+    "expected table",
+    "invalid reference"
+};
+
+static const uint8_t *unmarshal1(
+        UnmarshalState *st,
+        const uint8_t *data,
+        Dst *out,
+        int flags) {
+    const uint8_t *end = st->end;
+    uint8_t lead;
+    if ((flags & 0xFFFF) > DST_RECURSION_GUARD) {
+        longjmp(st->err, UMR_STACKOVERFLOW);
+    }
+#define EXTRA(N) if (data + N > end) longjmp(st->err, UMR_EOS)
+    EXTRA(1);
+    lead = data[0];
+    if (lead < 200) {
+        *out = dst_wrap_integer(lead);
+        return data + 1;
+    }
+    switch (lead) {
+        case LB_NIL:
+            *out = dst_wrap_nil();
+            return data + 1;
+        case LB_FALSE:
+            *out = dst_wrap_false();
+            return data + 1;
+        case LB_TRUE:
+            *out = dst_wrap_true();
+            return data + 1;
+        case LB_INTEGER:
+            /* Long integer */
+            EXTRA(5);
+            *out = dst_wrap_integer(
+                    (data[1]) |
+                    (data[2] << 8) |
+                    (data[3] << 16) |
+                    (data[4] << 24));
+            return data + 5;
+        case LB_REAL:
+            /* Real */
+            {
+                union {
+                    double d;
+                    uint8_t bytes[8];
+                } u;
+                EXTRA(9);
+#ifdef DST_BIG_ENDIAN
+                u.bytes[0] = data[8];
+                u.bytes[1] = data[7];
+                u.bytes[2] = data[6];
+                u.bytes[5] = data[5];
+                u.bytes[4] = data[4];
+                u.bytes[5] = data[3];
+                u.bytes[6] = data[2];
+                u.bytes[7] = data[1];
+#else
+                memcpy(&u.bytes, data + 1, sizeof(double));
+#endif
+                *out = dst_wrap_real(u.d);
+                dst_array_push(&st->lookup, *out);
+                return data + 9;
+            }
+        case LB_STRING:
+        case LB_SYMBOL:
+        case LB_BUFFER:
+            {
+                Dst lenv;
+                int32_t len;
+                data = unmarshal1(st, data + 1, &lenv, flags + 1);
+                if (!dst_checktype(lenv, DST_INTEGER)) longjmp(st->err, UMR_EXPECTED_INTEGER);
+                len = dst_unwrap_integer(lenv);
+                EXTRA(len);
+                if (lead == LB_STRING) {
+                    const uint8_t *str = dst_string(data, len);
+                    *out = dst_wrap_string(str);
+                } else if (lead == LB_SYMBOL) {
+                    const uint8_t *str = dst_symbol(data, len);
+                    *out = dst_wrap_symbol(str);
+                } else { /* (lead == LB_BUFFER) */
+                    DstBuffer *buffer = dst_buffer(len);
+                    buffer->count = len;
+                    memcpy(buffer->data, data, len);
+                    *out = dst_wrap_buffer(buffer);
+                }
+                dst_array_push(&st->lookup, *out);
+                return data + len;
+            }
+        case LB_REFERENCE:
+        case LB_ARRAY:
+        case LB_TUPLE:
+        case LB_STRUCT:
+        case LB_TABLE:
+        case LB_TABLE_PROTO:
+            /* Things that open with integers */
+            {
+                Dst lenv;
+                int32_t len, i;
+                data = unmarshal1(st, data + 1, &lenv, flags + 1);
+                if (!dst_checktype(lenv, DST_INTEGER)) longjmp(st->err, UMR_EXPECTED_INTEGER);
+                len = dst_unwrap_integer(lenv);
+                if (lead == LB_ARRAY) {
+                    /* Array */
+                    DstArray *array = dst_array(len);
+                    array->count = len;
+                    *out = dst_wrap_array(array);
+                    dst_array_push(&st->lookup, *out);
+                    for (i = 0; i < len; i++) {
+                        data = unmarshal1(st, data, array->data + i, flags + 1);
+                    }
+                } else if (lead == LB_TUPLE) {
+                    /* Tuple */
+                    Dst *tup = dst_tuple_begin(len);
+                    for (i = 0; i < len; i++) {
+                        data = unmarshal1(st, data, tup + i, flags + 1);
+                    }
+                    *out = dst_wrap_tuple(dst_tuple_end(tup));
+                    dst_array_push(&st->lookup, *out);
+                } else if (lead == LB_STRUCT) {
+                    /* Struct */
+                    DstKV *struct_ = dst_struct_begin(len);
+                    for (i = 0; i < len; i++) {
+                        Dst key, value;
+                        data = unmarshal1(st, data, &key, flags + 1);
+                        data = unmarshal1(st, data, &value, flags + 1);
+                        dst_struct_put(struct_, key, value);
+                    }
+                    *out = dst_wrap_struct(dst_struct_end(struct_));
+                    dst_array_push(&st->lookup, *out);
+                } else if (lead == LB_REFERENCE) {
+                    if (len < 0 || len >= st->lookup.count)
+                        longjmp(st->err, UMR_INVALID_REFERENCE);
+                    *out = st->lookup.data[len];
+                } else {
+                    /* Table */
+                    DstTable *t = dst_table(len);
+                    *out = dst_wrap_table(t);
+                    dst_array_push(&st->lookup, *out);
+                    if (lead == LB_TABLE_PROTO) {
+                        Dst proto;
+                        data = unmarshal1(st, data, &proto, flags + 1);
+                        if (!dst_checktype(proto, DST_TABLE)) longjmp(st->err, UMR_EXPECTED_TABLE);
+                        t->proto = dst_unwrap_table(proto);
+                    }
+                    for (i = 0; i < len; i++) {
+                        Dst key, value;
+                        data = unmarshal1(st, data, &key, flags + 1);
+                        data = unmarshal1(st, data, &value, flags + 1);
+                        dst_table_put(t, key, value);
+                    }
+                }
+                return data;
+            }
+        default:
+            longjmp(st->err, UMR_UNKNOWN);
+            return NULL;
+    }
+#undef EXTRA
+}
+
+int dst_unmarshal(
+        const uint8_t *bytes,
+        size_t len, 
+        int flags, 
+        Dst *out, 
+        const uint8_t **next) {
+    int status;
+    /* Avoid longjmp clobber warning in GCC */
+    UnmarshalState st; 
+    st.end = bytes + len;
+    dst_array_init(&st.lookup, 0);
+    if (!(status = setjmp(st.err))) {
+        const uint8_t *nextbytes = unmarshal1(&st, bytes, out, flags);
+        if (next) *next = nextbytes;
+    }
+    dst_array_deinit(&st.lookup);
+    return status;
+}
+
+/* C functions */
+
+static int cfun_marshal(DstArgs args) {
+    DstBuffer *buffer;
+    int status;
+    DST_MINARITY(args, 1);
+    DST_MAXARITY(args, 2);
+    if (args.n == 2) {
+        /* Buffer provided */
+        DST_ARG_BUFFER(buffer, args, 1);
+    } else {
+        buffer = dst_buffer(10);
+    }
+    status = dst_marshal(buffer, args.v[0], 0);
+    if (status) {
+        DST_THROW(args, mr_strings[status]);
+    }
+    DST_RETURN_BUFFER(args, buffer);
+}
+
+static int cfun_unmarshal(DstArgs args) {
+    const uint8_t *bytes;
+    int32_t len;
+    int status;
+    DST_FIXARITY(args, 1);
+    DST_ARG_BYTES(bytes, len, args, 0);
+    status = dst_unmarshal(bytes, (size_t) len, 0, args.ret, NULL);
+    if (status) {
+        DST_THROW(args, umr_strings[status]);
+    }
+    return DST_SIGNAL_OK;
+}
+
+static const DstReg cfuns[] = {
+    {"marsh.marshal", cfun_marshal},
+    {"marsh.unmarshal", cfun_unmarshal},
+    {NULL, NULL}
+};
+
+/* Module entry point */
+int dst_lib_marsh(DstArgs args) {
+    DstTable *env = dst_env_arg(args);
+    dst_env_cfuns(env, cfuns);
+    return 0;
+}
diff --git a/src/core/state.h b/src/core/state.h
index 15ce6c05..1678bbbc 100644
--- a/src/core/state.h
+++ b/src/core/state.h
@@ -45,6 +45,10 @@ extern DST_THREAD_LOCAL int dst_vm_stackn;
  * Set and unset by dst_run. */
 extern DST_THREAD_LOCAL DstFiber *dst_vm_fiber;
 
+/* The global registry for c functions. Used to store metadata
+ * along with otherwise bare c function pointers. */
+extern DST_THREAD_LOCAL DstTable *dst_vm_registry;
+
 /* Immutable value cache */
 extern DST_THREAD_LOCAL const uint8_t **dst_vm_cache;
 extern DST_THREAD_LOCAL uint32_t dst_vm_cache_capacity;
diff --git a/src/core/string.c b/src/core/string.c
index 043b62a9..f4bac39c 100644
--- a/src/core/string.c
+++ b/src/core/string.c
@@ -24,6 +24,7 @@
 #include <dst/dstcorelib.h>
 #include "gc.h"
 #include "util.h"
+#include "state.h"
 
 /* Begin building a string */
 uint8_t *dst_string_begin(int32_t length) {
@@ -229,7 +230,10 @@ static int32_t dst_escape_string_length(const uint8_t *str, int32_t slen) {
                 len += 2;
                 break;
             default:
-                len += 1;
+                if (str[i] < 32 || str[i] > 127)
+                    len += 4;
+                else
+                    len += 1;
                 break;
         }
     }
@@ -263,7 +267,14 @@ static void dst_escape_string_impl(uint8_t *buf, const uint8_t *str, int32_t len
                 buf[j++] = '\\';
                 break;
             default:
-                buf[j++] = c;
+                if (c < 32 || c > 127) {
+                    buf[j++] = '\\';
+                    buf[j++] = 'h';
+                    buf[j++] = dst_base64[(c >> 4) & 0xF];
+                    buf[j++] = dst_base64[c & 0xF];
+                } else {
+                    buf[j++] = c;
+                }
                 break;
         }
     }
@@ -332,6 +343,20 @@ void dst_description_b(DstBuffer *buffer, Dst x) {
                     n[0] == ':' ? n + 1 : n,
                     dst_unwrap_abstract(x));
         }
+    case DST_CFUNCTION:
+        {
+            Dst check = dst_table_get(dst_vm_registry, x);
+            if (dst_checktype(x, DST_SYMBOL)) {
+                dst_buffer_push_cstring(buffer, "<cfunction ");
+                dst_buffer_push_bytes(buffer,
+                        dst_unwrap_symbol(check),
+                        dst_string_length(dst_unwrap_symbol(check)));
+                dst_buffer_push_u8(buffer, '>');
+                break;
+            }
+            goto fallthrough;
+        }
+    fallthrough:
     default:
         string_description_b(buffer, dst_type_names[dst_type(x)] + 1, dst_unwrap_pointer(x));
         break;
@@ -390,6 +415,15 @@ const uint8_t *dst_description(Dst x) {
                     n[0] == ':' ? n + 1 : n,
                     dst_unwrap_abstract(x));
         }
+    case DST_CFUNCTION:
+        {
+            Dst check = dst_table_get(dst_vm_registry, x);
+            if (!dst_checktype(x, DST_NIL)) {
+                return dst_formatc("<cfunction %V>", check);
+            }
+            goto fallthrough;
+        }
+    fallthrough:
     default:
         return string_description(dst_type_names[dst_type(x)] + 1, dst_unwrap_pointer(x));
     }
diff --git a/src/core/util.c b/src/core/util.c
index 79b956fa..6b4152be 100644
--- a/src/core/util.c
+++ b/src/core/util.c
@@ -22,6 +22,7 @@
 
 #include <dst/dst.h>
 #include "util.h"
+#include "state.h"
 #include "gc.h"
 
 /* Base 64 lookup table for digits */
@@ -128,7 +129,11 @@ void dst_env_var(DstTable *env, const char *name, Dst val) {
 /* Load many cfunctions at once */
 void dst_env_cfuns(DstTable *env, const DstReg *cfuns) {
     while (cfuns->name) {
-        dst_env_def(env, cfuns->name, dst_wrap_cfunction(cfuns->cfun));
+        Dst name = dst_csymbolv(cfuns->name);
+        Dst fun = dst_wrap_cfunction(cfuns->cfun);
+        dst_env_def(env, cfuns->name, fun);
+        dst_table_put(dst_vm_registry, name, fun);
+        dst_table_put(dst_vm_registry, fun, name);
         cfuns++;
     }
 }
diff --git a/src/core/vm.c b/src/core/vm.c
index d1e85bdc..fbb97857 100644
--- a/src/core/vm.c
+++ b/src/core/vm.c
@@ -28,6 +28,7 @@
 #include "symcache.h"
 
 /* VM state */
+DST_THREAD_LOCAL DstTable *dst_vm_registry;
 DST_THREAD_LOCAL int dst_vm_stackn = 0;
 DST_THREAD_LOCAL DstFiber *dst_vm_fiber = NULL;
 
@@ -711,7 +712,7 @@ static void *op_lookup[255] = {
         } else if (dst_checktype(callee, DST_CFUNCTION)) {
             DstArgs args;
             args.n = fiber->stacktop - fiber->stackstart;
-            dst_fiber_cframe(fiber);
+            dst_fiber_cframe(fiber, dst_unwrap_cfunction(callee));
             retreg = dst_wrap_nil();
             args.v = fiber->data + fiber->frame;
             args.ret = &retreg;
@@ -735,7 +736,7 @@ static void *op_lookup[255] = {
         } else if (dst_checktype(callee, DST_CFUNCTION)) {
             DstArgs args;
             args.n = fiber->stacktop - fiber->stackstart;
-            dst_fiber_cframe(fiber);
+            dst_fiber_cframe(fiber, dst_unwrap_cfunction(callee));
             retreg = dst_wrap_nil();
             args.v = fiber->data + fiber->frame;
             args.ret = &retreg;
@@ -930,6 +931,9 @@ int dst_init() {
     dst_vm_roots = NULL;
     dst_vm_root_count = 0;
     dst_vm_root_capacity = 0;
+    /* Initialize registry */
+    dst_vm_registry = dst_table(0);
+    dst_gcroot(dst_wrap_table(dst_vm_registry));
     return 0;
 }
 
@@ -941,4 +945,5 @@ void dst_deinit() {
     dst_vm_roots = NULL;
     dst_vm_root_count = 0;
     dst_vm_root_capacity = 0;
+    dst_vm_registry = NULL;
 }
diff --git a/src/include/dst/dstcorelib.h b/src/include/dst/dstcorelib.h
index 93849b33..99e3ebc3 100644
--- a/src/include/dst/dstcorelib.h
+++ b/src/include/dst/dstcorelib.h
@@ -102,6 +102,7 @@ int dst_lib_table(DstArgs args);
 int dst_lib_fiber(DstArgs args);
 int dst_lib_os(DstArgs args);
 int dst_lib_string(DstArgs args);
+int dst_lib_marsh(DstArgs args);
 
 /* Useful for compiler */
 Dst dst_op_add(Dst lhs, Dst rhs);
diff --git a/src/parser/parse.c b/src/parser/parse.c
index c3dd1ab3..3f31ecd5 100644
--- a/src/parser/parse.c
+++ b/src/parser/parse.c
@@ -183,9 +183,9 @@ static void popstate(DstParser *p, Dst val) {
     }
 }
 
-static uint8_t checkescape(uint8_t c) {
+static int checkescape(uint8_t c) {
     switch (c) {
-        default: return 0;
+        default: return -1;
         case 'h': return 1;
         case 'n': return '\n'; 
         case 't': return '\t'; 
@@ -219,8 +219,8 @@ static int escapeh(DstParser *p, DstParseState *state, uint8_t c) {
 }
 
 static int escape1(DstParser *p, DstParseState *state, uint8_t c) {
-    uint8_t e = checkescape(c);
-    if (!e) {
+    int e = checkescape(c);
+    if (e < 0) {
         p->error = "invalid string escape sequence";
         return 1;
     }
@@ -229,7 +229,7 @@ static int escape1(DstParser *p, DstParseState *state, uint8_t c) {
         state->argn = 0;
         state->consumer = escapeh;
     } else {
-        push_buf(p, e);
+        push_buf(p, (uint8_t) e);
         state->consumer = stringchar;
     }
     return 1;
diff --git a/test/suite1.dst b/test/suite1.dst
index affa737b..f234b09d 100644
--- a/test/suite1.dst
+++ b/test/suite1.dst
@@ -127,4 +127,26 @@
 (assert (= (string.find "123" "abc123def") 3) "string.find positive")
 (assert (= (string.find "1234" "abc123def") nil) "string.find negative")
 
+# Marshal
+
+(defn testmarsh [x msg]
+  (def marshx (marsh.marshal x))
+  (def out (-> marshx marsh.unmarshal marsh.marshal))
+  (assert (= (string marshx) (string out)) msg))
+
+(testmarsh nil "marshal nil")
+(testmarsh false "marshal false")
+(testmarsh true "marshal true")
+(testmarsh 1 "marshal small integers")
+(testmarsh -1 "marshal integers (-1)")
+(testmarsh 199 "marshal small integers (199)")
+(testmarsh 1.0 "marshal double")
+(testmarsh "doctordolittle" "marshal string")
+(testmarsh :chickenshwarma "marshal symbol")
+(testmarsh @"oldmcdonald" "marshal buffer")
+(testmarsh @[1 2 3 4 5] "marshal array")
+(testmarsh [tuple 1 2 3 4 5] "marshal tuple")
+(testmarsh @{1 2 3 4}  "marshal table")
+(testmarsh {1 2 3 4}  "marshal struct")
+
 (end-suite)