diff --git a/include/dst/dst.h b/include/dst/dst.h
new file mode 100644
index 00000000..6f2b61e5
--- /dev/null
+++ b/include/dst/dst.h
@@ -0,0 +1,575 @@
+/*
+* Copyright (c) 2017 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.
+*/
+
+#ifndef DST_H_defined
+#define DST_H_defined
+
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdarg.h>
+
+/*
+ * Detect OS and endianess.
+ * From webkit source. 
+ */
+
+/* Unix? */
+#if defined(_AIX) \
+    || defined(__APPLE__) /* Darwin */ \
+    || defined(__FreeBSD__) || defined(__DragonFly__) \
+    || defined(__FreeBSD_kernel__) \
+    || defined(__GNU__) /* GNU/Hurd */ \
+    || defined(__linux__) \
+    || defined(__NetBSD__) \
+    || defined(__OpenBSD__) \
+    || defined(__QNXNTO__) \
+    || defined(sun) || defined(__sun) /* Solaris */ \
+    || defined(unix) || defined(__unix) || defined(__unix__)
+#define DST_UNIX 1
+#endif
+
+/* Windows? */
+#if defined(WIN32) || defined(_WIN32)
+#define DST_WINDOWS 1
+#endif
+
+/* 64-bit mode? */
+#if ((defined(__x86_64__) || defined(_M_X64)) \
+     && (defined(DST_UNIX) || defined(DST_WINDOWS))) \
+    || (defined(__ia64__) && defined(__LP64__)) /* Itanium in LP64 mode */ \
+    || defined(__alpha__) /* DEC Alpha */ \
+    || (defined(__sparc__) && defined(__arch64__) || defined (__sparcv9)) /* BE */ \
+    || defined(__s390x__) /* S390 64-bit (BE) */ \
+    || (defined(__ppc64__) || defined(__PPC64__)) \
+    || defined(__aarch64__) /* ARM 64-bit */
+#define DST_64 1
+#else
+#define DST_32 1
+#endif
+
+/* Big endian? (Mostly equivallent to how WebKit does it) */
+#if defined(__MIPSEB__) /* MIPS 32-bit */ \
+    || defined(__ppc__) || defined(__PPC__) /* CPU(PPC) - PowerPC 32-bit */ \
+    || defined(__powerpc__) || defined(__powerpc) || defined(__POWERPC__) \
+    || defined(_M_PPC) || defined(__PPC) \
+    || defined(__ppc64__) || defined(__PPC64__) /* PowerPC 64-bit */ \
+    || defined(__sparc)   /* Sparc 32bit */  \
+    || defined(__sparc__) /* Sparc 64-bit */ \
+    || defined(__s390x__) /* S390 64-bit */ \
+    || defined(__s390__)  /* S390 32-bit */ \
+    || defined(__ARMEB__) /* ARM big endian */ \
+    || ((defined(__CC_ARM) || defined(__ARMCC__)) /* ARM RealView compiler */ \
+        && defined(__BIG_ENDIAN))
+#define DST_BIG_ENDIAN 1
+#endif
+
+/* What to do when out of memory */
+#ifndef DST_OUT_OF_MEMORY
+#include <stdio.h>
+#define DST_OUT_OF_MEMORY do { printf("out of memory\n"); exit(1); } while (0)
+#endif
+
+/* What to do when dst is used in unitialized state */
+#ifndef DST_PLEASE_INIT
+#include <stdio.h>
+#define DST_PLEASE_INIT do { printf("dst is uninitialized\n"); exit(1); } while (0)
+#endif
+
+#define DST_INTEGER_MIN INT64_MIN
+#define DST_INTEGER_MAX INT64_MAX
+
+/* Prevent some recursive functions from recursing too deeply
+ * ands crashing (the parser). Instead, error out. */
+#define DST_RECURSION_GUARD 1000
+
+/* Names of all of the types */
+extern const char *dst_type_names[15];
+
+/* Various types */
+typedef enum DstType {
+    DST_NIL = 0,
+    DST_REAL,
+    DST_INTEGER,
+    DST_BOOLEAN,
+    DST_STRING,
+    DST_SYMBOL,
+    DST_ARRAY,
+    DST_TUPLE,
+    DST_TABLE,
+    DST_STRUCT,
+    DST_FIBER,
+    DST_BUFFER,
+    DST_FUNCTION,
+    DST_CFUNCTION,
+    DST_USERDATA
+} DstType;
+
+/* A general dst value type */
+typedef struct DstValue DstValue;
+
+/* All of the dst types */
+typedef int DstBoolean;
+typedef struct DstFunction DstFunction;
+typedef struct DstArray DstArray;
+typedef struct DstBuffer DstBuffer;
+typedef struct DstTable DstTable;
+typedef struct DstFiber DstFiber;
+typedef int (*DstCFunction)(DstValue *argv, uint32_t argn);
+
+/* Other structs */
+typedef struct DstUserdataHeader DstUserdataHeader;
+typedef struct DstFuncDef DstFuncDef;
+typedef struct DstFuncEnv DstFuncEnv;
+typedef struct DstStackFrame DstStackFrame;
+typedef union DstValueUnion DstValueUnion;
+typedef struct DstUserType DstUserType;
+
+/* Union datatype */
+union DstValueUnion {
+    DstBoolean boolean;
+    double real;
+    int64_t integer;
+    uint64_t uinteger;
+    DstArray *array;
+    DstBuffer *buffer;
+    DstTable *table;
+    DstFiber *fiber;
+    const DstValue *tuple;
+    DstCFunction cfunction;
+    DstFunction *function;
+    const DstValue *st;
+    const uint8_t *string;
+    void *pointer;
+};
+
+/* The general dst value type. Contains a large union and
+ * the type information of the value */
+struct DstValue {
+    DstValueUnion as;
+    DstType type;
+};
+
+/* A lightweight green thread in dst. Does not correspond to
+ * operating system threads. */
+struct DstFiber {
+    DstValue ret; /* Return value */
+    DstValue *data;
+    DstFiber *parent;
+    uint32_t frame; /* Index of the stack frame */
+    uint32_t frametop; /* Index of top of stack frame */
+    uint32_t stacktop; /* Top of stack. Where values are pushed and popped from. */
+    uint32_t capacity;
+    enum {
+        DST_FIBER_PENDING = 0,
+        DST_FIBER_ALIVE,
+        DST_FIBER_DEAD,
+        DST_FIBER_ERROR
+    } status;
+};
+
+/* A stack frame on the fiber. Is stored along with the stack values. */
+struct DstStackFrame {
+    DstFunction *func;
+    uint32_t *pc;
+    uint32_t prevframe;
+};
+
+/* Number of DstValues a frame takes up in the stack */
+#define DST_FRAME_SIZE ((sizeof(DstStackFrame) + sizeof(DstValue) - 1)/ sizeof(DstValue))
+
+/* A dynamic array type. */
+struct DstArray {
+    DstValue *data;
+    uint32_t count;
+    uint32_t capacity;
+};
+
+/* A bytebuffer type. Used as a mutable string or string builder. */
+struct DstBuffer {
+    uint8_t *data;
+    uint32_t count;
+    uint32_t capacity;
+};
+
+/* A mutable associative data type. Backed by a hashtable. */
+struct DstTable {
+    DstValue *data;
+    uint32_t count;
+    uint32_t capacity;
+    uint32_t deleted;
+};
+
+/* Some function defintion flags */
+#define DST_FUNCDEF_FLAG_VARARG 1
+#define DST_FUNCDEF_FLAG_NEEDSENV 4
+
+/* A function definition. Contains information needed to instantiate closures. */
+struct DstFuncDef {
+    uint32_t *environments; /* Which environments to capture from parent. */
+    DstValue *constants; /* Contains strings, FuncDefs, etc. */
+    uint32_t *bytecode;
+
+    uint32_t flags;
+    uint32_t slotcount; /* The amount of stack space required for the function */
+    uint32_t arity; /* Not including varargs */
+    uint32_t constants_length;
+    uint32_t bytecode_length;
+    uint32_t environments_length; 
+};
+
+/* A fuction environment */
+struct DstFuncEnv {
+    union {
+        DstFiber *fiber;
+        DstValue *values;
+    } as;
+    uint32_t length; /* Size of environment */
+    uint32_t offset; /* Stack offset when values still on stack. If offset is 0, then
+        environment is no longer on the stack. */
+};
+
+/* A function */
+struct DstFunction {
+    DstFuncDef *def;
+    /* Consider allocating envs with entire function struct */
+    DstFuncEnv **envs;
+};
+
+/* Defines a type for userdata */
+struct DstUserType {
+    const char *name;
+    int (*serialize)(void *data, uint32_t len);
+    int (*deserialize)();
+    void (*finalize)(void *data, uint32_t len);
+};
+
+/* Contains information about userdata */
+struct DstUserdataHeader {
+    const DstUserType *type;
+    uint32_t size;
+};
+
+/* The VM state. Rather than a struct that is passed
+ * around, the vm state is global for simplicity and performance. */
+
+/* TODO - somehow wrap these for windows dynamic linking. Either that,
+ * or force static linking. see
+ * https://stackoverflow.com/questions/19373061/what-happens-to-global-and-static-variables-in-a-shared-library-when-it-is-dynam */
+
+/* Garbage collection */
+extern void *dst_vm_blocks;
+extern uint32_t dst_vm_memory_interval;
+extern uint32_t dst_vm_next_collection;
+
+/* Immutable value cache */
+extern DstValue *dst_vm_cache;
+extern uint32_t dst_vm_cache_capacity;
+extern uint32_t dst_vm_cache_count;
+extern uint32_t dst_vm_cache_deleted;
+
+/* Syscall table */
+extern DstCFunction dst_vm_syscalls[256];
+
+/* GC roots - TODO consider a top level fiber pool (per thread?) */
+extern DstFiber *dst_vm_fiber;
+
+/* Array functions */
+DstArray *dst_array(uint32_t capacity);
+DstArray *dst_array_init(DstArray *array, uint32_t capacity);
+void dst_array_deinit(DstArray *array);
+void dst_array_ensure(DstArray *array, uint32_t capacity);
+void dst_array_setcount(DstArray *array, uint32_t count);
+void dst_array_push(DstArray *array, DstValue x);
+DstValue dst_array_pop(DstArray *array);
+DstValue dst_array_peek(DstArray *array);
+
+/* Buffer functions */
+DstBuffer *dst_buffer(uint32_t capacity);
+DstBuffer *dst_buffer_init(DstBuffer *buffer, uint32_t capacity);
+void dst_buffer_deinit(DstBuffer *buffer);
+void dst_buffer_ensure(DstBuffer *buffer, uint32_t capacity);
+void dst_buffer_extra(DstBuffer *buffer, uint32_t n);
+void dst_buffer_push_bytes(DstBuffer *buffer, const uint8_t *string, uint32_t len);
+void dst_buffer_push_cstring(DstBuffer *buffer, const char *cstring);
+void dst_buffer_push_u8(DstBuffer *buffer, uint8_t x);
+void dst_buffer_push_u16(DstBuffer *buffer, uint16_t x);
+void dst_buffer_push_u32(DstBuffer *buffer, uint32_t x);
+void dst_buffer_push_u64(DstBuffer *buffer, uint64_t x);
+
+/* Tuple */
+#define dst_tuple_raw(t) ((uint32_t *)(t) - 2)
+#define dst_tuple_length(t) (dst_tuple_raw(t)[0])
+#define dst_tuple_hash(t) (dst_tuple_raw(t)[1])
+DstValue *dst_tuple_begin(uint32_t length);
+const DstValue *dst_tuple_end(DstValue *tuple);
+const DstValue *dst_tuple_n(DstValue *values, uint32_t n);
+
+/* String/Symbol functions */
+#define dst_string_raw(s) ((uint32_t *)(s) - 2)
+#define dst_string_length(s) (dst_string_raw(s)[0])
+#define dst_string_hash(s) (dst_string_raw(s)[1])
+uint8_t *dst_string_begin(uint32_t length);
+const uint8_t *dst_string_end(uint8_t *str);
+const uint8_t *dst_string(const uint8_t *buf, uint32_t len);
+const uint8_t *dst_cstring(const char *cstring);
+int dst_string_compare(const uint8_t *lhs, const uint8_t *rhs);
+const uint8_t *dst_string_unique(const uint8_t *buf, uint32_t len);
+const uint8_t *dst_cstring_unique(const char *s);
+const uint8_t *dst_description(DstValue x);
+const uint8_t *dst_to_string(DstValue x);
+#define dst_cstringv(cstr) dst_wrap_string(dst_cstring(cstr))
+#define dst_cstrings(cstr) dst_wrap_symbol(dst_cstring(cstr))
+const uint8_t *dst_formatc(const char *format, ...);
+void dst_puts(const uint8_t *str);
+
+/* Structs */
+#define dst_struct_raw(t) ((uint32_t *)(t) - 2)
+#define dst_struct_length(t) (dst_struct_raw(t)[0])
+#define dst_struct_capacity(t) (dst_struct_length(t) * 4)
+#define dst_struct_hash(t) (dst_struct_raw(t)[1])
+DstValue *dst_struct_begin(uint32_t count);
+void dst_struct_put(DstValue *st, DstValue key, DstValue value);
+const DstValue *dst_struct_end(DstValue *st);
+DstValue dst_struct_get(const DstValue *st, DstValue key);
+DstValue dst_struct_next(const DstValue *st, DstValue key);
+DstTable *dst_struct_to_table(const DstValue *st);
+
+/* Table functions */
+DstTable *dst_table(uint32_t capacity);
+DstTable *dst_table_init(DstTable *table, uint32_t capacity);
+void dst_table_deinit(DstTable *table);
+DstValue dst_table_get(DstTable *t, DstValue key);
+DstValue dst_table_remove(DstTable *t, DstValue key);
+void dst_table_put(DstTable *t, DstValue key, DstValue value);
+DstValue dst_table_next(DstTable *t, DstValue key);
+const DstValue *dst_table_to_struct(DstTable *t);
+
+/* Fiber */
+DstFiber *dst_fiber(uint32_t capacity);
+#define dst_stack_frame(s) ((DstStackFrame *)((s) - DST_FRAME_SIZE))
+#define dst_fiber_frame(f) dst_stack_frame((f)->data + (f)->frame)
+DstFiber *dst_fiber_reset(DstFiber *fiber);
+void dst_fiber_setcapacity(DstFiber *fiber, uint32_t n);
+void dst_fiber_push(DstFiber *fiber, DstValue x);
+void dst_fiber_push2(DstFiber *fiber, DstValue x, DstValue y);
+void dst_fiber_push3(DstFiber *fiber, DstValue x, DstValue y, DstValue z);
+void dst_fiber_pushn(DstFiber *fiber, const DstValue *arr, uint32_t n);
+DstValue dst_fiber_popvalue(DstFiber *fiber);
+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_tail(DstFiber *fiber);
+void dst_fiber_popframe(DstFiber *fiber);
+
+/* Functions */
+void dst_function_detach(DstFunction *func);
+
+/* Assembly */
+typedef enum {
+    DST_ASSEMBLE_OK,
+    DST_ASSEMBLE_ERROR
+} DstAssembleStatus;
+typedef struct DstAssembleResult DstAssembleResult;
+typedef struct DstAssembleOptions DstAssembleOptions;
+struct DstAssembleResult {
+    union {
+        DstFuncDef *def;
+        const uint8_t *error;
+    } result;
+    DstAssembleStatus status;
+};
+struct DstAssembleOptions {
+    DstValue parsemap;
+    DstValue source;
+    uint32_t flags;
+};
+DstAssembleResult dst_asm(DstAssembleOptions opts);
+DstFunction *dst_asm_func(DstAssembleResult result);
+
+/* Treat similar types through uniform interfaces for iteration */
+int dst_seq_view(DstValue seq, const DstValue **data, uint32_t *len);
+int dst_chararray_view(DstValue str, const uint8_t **data, uint32_t *len);
+int dst_hashtable_view(DstValue tab, const DstValue **data, uint32_t *len, uint32_t *cap);
+
+/* Userdata */
+#define dst_userdata_header(u) ((DstUserdataHeader *)(u) - 1)
+#define dst_userdata_type(u) (dst_userdata_header(u)->type)
+#define dst_userdata_size(u) (dst_userdata_header(u)->size)
+
+/* Value functions */
+int dst_truthy(DstValue v);
+int dst_equals(DstValue x, DstValue y);
+uint32_t dst_hash(DstValue x);
+int dst_compare(DstValue x, DstValue y);
+uint32_t dst_calchash_array(const DstValue *array, uint32_t len);
+DstValue dst_get(DstValue ds, DstValue key);
+void dst_put(DstValue ds, DstValue key, DstValue value);
+DstValue dst_next(DstValue ds, DstValue key);
+uint32_t dst_length(DstValue x);
+uint32_t dst_capacity(DstValue x);
+DstValue dst_getindex(DstValue ds, uint32_t index);
+void dst_setindex(DstValue ds, DstValue value, uint32_t index);
+
+/* Utils */
+int64_t dst_real_to_integer(double real);
+double dst_integer_to_real(int64_t integer);
+
+/* Parsing */
+typedef enum {
+    DST_PARSE_OK,
+    DST_PARSE_ERROR,
+    DST_PARSE_UNEXPECTED_EOS
+} DstParseStatus;
+typedef struct DstParseResult DstParseResult;
+struct DstParseResult {
+    union {
+        DstValue value;
+        const uint8_t *error;
+    } result;
+    DstValue map;
+    uint32_t bytes_read;
+    DstParseStatus status;
+};
+DstParseResult dst_parse(const uint8_t *src, uint32_t len);
+DstParseResult dst_parsec(const char *src);
+
+/* VM functions */
+int dst_init();
+void dst_deinit();
+int dst_continue();
+int dst_run(DstValue callee);
+DstValue dst_transfer(DstFiber *fiber, DstValue x);
+
+/* Wrap data in DstValue */
+DstValue dst_wrap_nil();
+DstValue dst_wrap_real(double x);
+DstValue dst_wrap_integer(int64_t x);
+DstValue dst_wrap_boolean(int x);
+DstValue dst_wrap_string(const uint8_t *x);
+DstValue dst_wrap_symbol(const uint8_t *x);
+DstValue dst_wrap_array(DstArray *x);
+DstValue dst_wrap_tuple(const DstValue *x);
+DstValue dst_wrap_struct(const DstValue *x);
+DstValue dst_wrap_fiber(DstFiber *x);
+DstValue dst_wrap_buffer(DstBuffer *x);
+DstValue dst_wrap_function(DstFunction *x);
+DstValue dst_wrap_cfunction(DstCFunction x);
+DstValue dst_wrap_table(DstTable *x);
+DstValue dst_wrap_userdata(void *x);
+
+/* GC */
+
+/* The metadata header associated with an allocated block of memory */
+#define dst_gc_header(mem) ((DstGCMemoryHeader *)(mem) - 1)
+
+#define DST_MEM_TYPEBITS 0xFF
+#define DST_MEM_REACHABLE 0x100
+#define DST_MEM_DISABLED 0x200
+
+#define dst_gc_settype(m, t) ((dst_gc_header(m)->flags |= (0xFF & (t))))
+#define dst_gc_type(m) (dst_gc_header(m)->flags & 0xFF)
+
+#define dst_gc_mark(m) (dst_gc_header(m)->flags |= DST_MEM_REACHABLE)
+#define dst_gc_unmark(m) (dst_gc_header(m)->flags &= ~DST_MEM_COLOR)
+#define dst_gc_reachable(m) (dst_gc_header(m)->flags & DST_MEM_REACHABLE)
+
+
+/* Memory header struct. Node of a linked list of memory blocks. */
+typedef struct DstGCMemoryHeader DstGCMemoryHeader;
+struct DstGCMemoryHeader {
+    DstGCMemoryHeader *next;
+    uint32_t flags;
+};
+
+/* Memory types for the GC. Different from DstType to include funcenv and funcdef. */
+typedef enum DstMemoryType DstMemoryType;
+enum DstMemoryType {
+    DST_MEMORY_NONE,
+    DST_MEMORY_STRING,
+    DST_MEMORY_ARRAY,
+    DST_MEMORY_TUPLE,
+    DST_MEMORY_TABLE,
+    DST_MEMORY_STRUCT,
+    DST_MEMORY_FIBER,
+    DST_MEMORY_BUFFER,
+    DST_MEMORY_FUNCTION,
+    DST_MEMORY_USERDATA,
+    DST_MEMORY_FUNCENV,
+    DST_MEMORY_FUNCDEF
+};
+
+/* Prevent GC from freeing some memory. */
+#define dst_disablegc(m) (dst_gc_header(m)->flags |= DST_MEM_DISABLED, (m))
+
+/* To allocate collectable memory, one must calk dst_alloc, initialize the memory,
+ * and then call when dst_enablegc when it is initailize and reachable by the gc (on the DST stack) */
+void *dst_alloc(DstMemoryType type, size_t size);
+#define dst_enablegc(m) (dst_gc_header(m)->flags &= ~DST_MEM_DISABLED, (m))
+
+/* When doing C interop, it is often needed to disable GC on a value.
+ * This is needed when a garbage collection could occur in the middle
+ * of a c function. This could happen, for example, if one calls back
+ * into dst inside of a c function. The pin and unpin functions toggle
+ * garbage collection on a value when needed. Note that no dst functions
+ * will call gc when you don't want it to. GC only happens automatically
+ * in the interpreter loop. */
+void dst_pin(DstValue x);
+void dst_unpin(DstValue x);
+
+/* Specific types can also be pinned and unpinned as well. */
+#define dst_pin_table dst_disablegc
+#define dst_pin_array dst_disablegc
+#define dst_pin_buffer dst_disablegc
+#define dst_pin_function dst_disablegc
+#define dst_pin_fiber dst_disablegc
+#define dst_pin_string(s) dst_disablegc(dst_string_raw(s))
+#define dst_pin_symbol(s) dst_disablegc(dst_string_raw(s))
+#define dst_pin_tuple(s) dst_disablegc(dst_tuple_raw(s))
+#define dst_pin_struct(s) dst_disablegc(dst_struct_raw(s))
+#define dst_pin_userdata(s) dst_disablegc(dst_userdata_header(s))
+
+#define dst_unpin_table dst_enablegc
+#define dst_unpin_array dst_enablegc
+#define dst_unpin_buffer dst_enablegc
+#define dst_unpin_function dst_enablegc
+#define dst_unpin_fiber dst_enablegc
+#define dst_unpin_string(s) dst_enablegc(dst_string_raw(s))
+#define dst_unpin_symbol(s) dst_enablegc(dst_string_raw(s))
+#define dst_unpin_tuple(s) dst_enablegc(dst_tuple_raw(s))
+#define dst_unpin_struct(s) dst_enablegc(dst_struct_raw(s))
+#define dst_unpin_userdata(s) dst_enablegc(dst_userdata_header(s))
+
+void dst_mark(DstValue x);
+void dst_sweep();
+
+/* Collect some memory */
+void dst_collect();
+
+/* Clear all memory. */
+void dst_clear_memory();
+
+/* Run garbage collection if needed */
+#define dst_maybe_collect() do {\
+    if (dst_vm_next_collection >= dst_vm_memory_interval) dst_collect(); } while (0)
+
+#endif /* DST_H_defined */