diff --git a/lib/cocoa/TBinaryProtocol.m b/lib/cocoa/TBinaryProtocol.m
new file mode 100644
index 0000000..cd239de
--- /dev/null
+++ b/lib/cocoa/TBinaryProtocol.m
@@ -0,0 +1,399 @@
+#import "TBinaryProtocol.h"
+
+int32_t VERSION_1 = 0x80010000;
+int32_t VERSION_MASK = 0xffff0000;
+
+
+@implementation TBinaryProtocol
+
+- (id) initWithTransport: (id <TTransport>) transport
+{
+  return [self initWithTransport: transport strictRead: NO strictWrite: NO];
+}
+
+- (id) initWithTransport: (id <TTransport>) transport 
+              strictRead: (BOOL) strictRead
+             strictWrite: (BOOL) strictWrite
+{
+  self = [super init];
+  mTransport = [transport retain];
+  mStrictRead = strictRead;
+  mStrictWrite = strictWrite;
+  return self;
+}
+
+
+- (id <TTransport>) transport
+{
+  return mTransport;
+}
+
+
+- (NSString *) readStringBody: (int) size
+{
+  char buff[size+1];
+  [mTransport readAll: (uint8_t *) buff offset: 0 length: size];
+  buff[size] = 0;
+  return [NSString stringWithUTF8String: buff];
+}
+
+
+- (void) readMessageBeginWithName: (NSString **) name
+                             type: (int *) type
+                       sequenceID: (int *) sequenceID
+{
+  int size = [self readI32];
+  if (size < 0) {
+    int version = size & VERSION_MASK;
+    if (version != VERSION_1) {
+      @throw [NSException exceptionWithName: @"TProtocolException"
+                          reason: @"Bad version in readMessageBegin"
+                          userInfo: nil];
+    }
+    if (type != NULL) {
+      *type = version & 0x00FF;
+    }
+    NSString * messageName = [self readString];
+    if (name != NULL) {
+      *name = messageName;
+    }
+    int seqID = [self readI32];
+    if (sequenceID != NULL) {
+      *sequenceID = seqID;
+    }
+  } else {
+    if (mStrictRead) {
+      @throw [NSException exceptionWithName: @"TProtocolException"
+                          reason: @"Missing version in readMessageBegin, old client?"
+                          userInfo: nil];
+    }
+    NSString * messageName = [self readStringBody: size];
+    if (name != NULL) {
+      *name = messageName;
+    }
+    int messageType = [self readByte];
+    if (type != NULL) {
+      *type = messageType;
+    }
+    int seqID = [self readI32];
+    if (sequenceID != NULL) {
+      *sequenceID = seqID;
+    }
+  }
+}
+
+
+- (void) readMessageEnd {}
+
+
+- (void) readStructBeginWithName: (NSString **) name
+{
+  if (name != NULL) {
+    *name = nil;
+  }
+}
+
+
+- (void) readStructEnd {}
+
+
+- (void) readFieldBeginWithName: (NSString **) name
+                           type: (int *) fieldType
+                        fieldID: (int *) fieldID
+{
+  if (name != NULL) {
+    *name = nil;
+  }
+  int ft = [self readByte];
+  if (fieldType != NULL) {
+    *fieldType = ft;
+  }    
+  if (ft != TType_STOP) {
+    int fid = [self readI16];
+    if (fieldID != NULL) {
+      *fieldID = fid;
+    }
+  }
+}
+
+
+- (void) readFieldEnd {}
+
+
+- (int32_t) readI32
+{
+  uint8_t i32rd[4];
+  [mTransport readAll: i32rd offset: 0 length: 4];
+  return
+    ((i32rd[0] & 0xff) << 24) |
+    ((i32rd[1] & 0xff) << 16) |
+    ((i32rd[2] & 0xff) <<  8) |
+    ((i32rd[3] & 0xff));
+}
+
+
+- (NSString *) readString
+{
+  int size = [self readI32];
+  return [self readStringBody: size];
+}
+
+
+- (BOOL) readBool
+{
+  return [self readByte] == 1;
+}
+
+- (uint8_t) readByte
+{
+  uint8_t myByte;
+  [mTransport readAll: &myByte offset: 0 length: 1];
+  return myByte;
+}
+
+- (short) readI16
+{
+  uint8_t buff[2];
+  [mTransport readAll: buff offset: 0 length: 2];
+  return (short)
+    (((buff[0] & 0xff) << 8) |
+     ((buff[1] & 0xff)));
+  return 0;
+}
+
+- (int64_t) readI64;
+{
+  uint8_t i64rd[8];
+  [mTransport readAll: i64rd offset: 0 length: 8];
+  return
+    ((int64_t)(i64rd[0] & 0xff) << 56) |
+    ((int64_t)(i64rd[1] & 0xff) << 48) |
+    ((int64_t)(i64rd[2] & 0xff) << 40) |
+    ((int64_t)(i64rd[3] & 0xff) << 32) |
+    ((int64_t)(i64rd[4] & 0xff) << 24) |
+    ((int64_t)(i64rd[5] & 0xff) << 16) |
+    ((int64_t)(i64rd[6] & 0xff) <<  8) |
+    ((int64_t)(i64rd[7] & 0xff));
+}
+
+- (double) readDouble;
+{
+  // FIXME - will this get us into trouble on PowerPC?
+  int64_t ieee754 = [self readI64];
+  return *((double *) &ieee754);
+}
+
+
+- (NSData *) readBinary
+{
+  int32_t size = [self readI32];
+  uint8_t * buff = malloc(size);
+  if (buff == NULL) {
+    @throw [NSException exceptionWithName: @"Out of memory" 
+                        reason: [NSString stringWithFormat: @"Unable to allocate %d bytes trying to read binary data.",
+                                          size]
+                        userInfo: nil];
+  }
+  [mTransport readAll: buff offset: 0 length: size];
+  return [NSData dataWithBytesNoCopy: buff length: size];
+}
+
+
+- (void) readMapBeginWithKeyType: (int *) keyType
+                       valueType: (int *) valueType
+                            size: (int *) size
+{
+  int kt = [self readByte];
+  int vt = [self readByte];
+  int s = [self readI32];
+  if (keyType != NULL) {
+    *keyType = kt;
+  }
+  if (valueType != NULL) {
+    *valueType = vt;
+  }
+  if (size != NULL) {
+    *size = s;
+  }
+}
+
+- (void) readMapEnd {}
+
+
+- (void) readSetBeginWithElementType: (int *) elementType
+                                size: (int *) size
+{
+  int et = [self readByte];
+  int s = [self readI32];
+  if (elementType != NULL) {
+    *elementType = et;
+  }
+  if (size != NULL) {
+    *size = s;
+  }
+}
+
+
+- (void) readSetEnd {}
+
+
+- (void) readListBeginWithElementType: (int *) elementType
+                                 size: (int *) size
+{
+  int et = [self readByte];
+  int s = [self readI32];
+  if (elementType != NULL) {
+    *elementType = et;
+  }
+  if (size != NULL) {
+    *size = s;
+  }
+}
+
+
+- (void) readListEnd {}
+
+
+- (void) writeByte: (uint8_t) value
+{
+  [mTransport write: &value offset: 0 length: 1];
+}
+
+
+- (void) writeMessageBeginWithName: (NSString *) name
+                              type: (int) messageType
+                        sequenceID: (int) sequenceID
+{
+  if (mStrictWrite) {
+    int version = VERSION_1 | messageType;
+    [self writeI32: version];
+    [self writeString: name];
+    [self writeI32: sequenceID];
+  } else {
+    [self writeString: name];
+    [self writeByte: messageType];
+    [self writeI32: sequenceID];
+  }
+}
+
+
+- (void) writeMessageEnd {}
+
+
+- (void) writeStructBeginWithName: (NSString *) name {}
+
+
+- (void) writeStructEnd {}
+
+
+- (void) writeFieldBeginWithName: (NSString *) name
+                            type: (int) fieldType
+                         fieldID: (int) fieldID
+{
+  [self writeByte: fieldType];
+  [self writeI16: fieldID];
+}
+
+
+- (void) writeI32: (int32_t) value
+{
+  uint8_t buff[4];
+  buff[0] = 0xFF & (value >> 24);
+  buff[1] = 0xFF & (value >> 16);
+  buff[2] = 0xFF & (value >> 8);
+  buff[3] = 0xFF & value;
+  [mTransport write: buff offset: 0 length: 4];
+}
+
+- (void) writeI16: (short) value
+{
+  uint8_t buff[2];
+  buff[0] = 0xff & (value >> 8);
+  buff[1] = 0xff & value;
+  [mTransport write: buff offset: 0 length: 2];
+}
+
+
+- (void) writeI64: (int64_t) value
+{
+  uint8_t buff[8];
+  buff[0] = 0xFF & (value >> 56);
+  buff[1] = 0xFF & (value >> 48);
+  buff[2] = 0xFF & (value >> 40);
+  buff[3] = 0xFF & (value >> 32);
+  buff[4] = 0xFF & (value >> 24);
+  buff[5] = 0xFF & (value >> 16);
+  buff[6] = 0xFF & (value >> 8);
+  buff[7] = 0xFF & value;
+  [mTransport write: buff offset: 0 length: 8];
+}
+
+- (void) writeDouble: (double) value
+{
+  // spit out IEEE 754 bits - FIXME - will this get us in trouble on
+  // PowerPC?
+  [self writeI64: *((int64_t *) &value)];
+}
+
+- (void) writeString: (NSString *) value
+{
+  const char * utf8Bytes = [value UTF8String];
+  size_t length = strlen(utf8Bytes);
+  [self writeI32: length];
+  [mTransport write: (uint8_t *) utf8Bytes offset: 0 length: length];
+}
+
+
+- (void) writeBinary: (NSData *) data 
+{
+  [self writeI32: [data length]];
+  [mTransport write: [data bytes] offset: 0 length: [data length]];
+}
+
+- (void) writeFieldStop
+{
+  [self writeByte: TType_STOP];
+}
+
+
+- (void) writeFieldEnd {}
+
+
+- (void) writeMapBeginWithKeyType: (int) keyType
+                        valueType: (int) valueType
+                             size: (int) size
+{
+  [self writeByte: keyType];
+  [self writeByte: valueType];
+  [self writeI32: size];
+}
+
+- (void) writeMapEnd {}
+
+
+- (void) writeSetBeginWithElementType: (int) elementType
+                                 size: (int) size
+{
+  [self writeByte: elementType];
+  [self writeI32: size];
+}
+
+- (void) writeSetEnd {}
+
+
+- (void) writeListBeginWithElementType: (int) elementType
+                                  size: (int) size
+{
+  [self writeByte: elementType];
+  [self writeI32: size];
+}
+
+- (void) writeListEnd {}
+
+
+- (void) writeBool: (BOOL) value
+{
+  [self writeByte: (value ? 1 : 0)];
+}
+
+@end