diff --git a/main.c b/main.c
index 944bd83..b8824ab 100644
--- a/main.c
+++ b/main.c
@@ -75,7 +75,7 @@ static void repl(CState *state)
     cosmoV_pushString(state, "input");
     cosmoV_pushCFunction(state, cosmoB_input);
 
-    cosmoV_register(state, 2);
+    cosmoV_addGlobals(state, 2);
 
     while (_ACTIVE) {
         if (!(line = linenoise("> "))) { // better than gets()
@@ -130,7 +130,7 @@ static bool runFile(CState *state, const char *fileName)
     cosmoV_pushString(state, "input");
     cosmoV_pushCFunction(state, cosmoB_input);
 
-    cosmoV_register(state, 1);
+    cosmoV_addGlobals(state, 1);
 
     ret = interpret(state, script, fileName);
 
diff --git a/src/cmem.c b/src/cmem.c
index a931ba9..02ff584 100644
--- a/src/cmem.c
+++ b/src/cmem.c
@@ -6,6 +6,7 @@
 #include "cstate.h"
 #include "ctable.h"
 #include "cvalue.h"
+#include "cvm.h"
 
 // realloc wrapper
 void *cosmoM_reallocate(CState *state, void *buf, size_t oldSize, size_t newSize)
@@ -246,22 +247,23 @@ static void sweep(CState *state)
                 prev->next = object;
             }
 
+            // call __gc on the object
+            CObjObject *protoObject = cosmoO_grabProto(oldObj);
+            CValue res;
+
+            // use user-defined __gc
+            if (protoObject != NULL && cosmoO_getIString(state, protoObject, ISTRING_GC, &res)) {
+                cosmoV_pushValue(state, res);
+                cosmoV_pushRef(state, (CObj *)oldObj);
+                cosmoV_call(state, 1, 0);
+            }
+
+
             cosmoO_free(state, oldObj);
         }
     }
 }
 
-static void markUserRoots(CState *state)
-{
-    CObj *root = state->userRoots;
-
-    // traverse userRoots and mark all the object
-    while (root != NULL) {
-        markObject(state, root);
-        root = root->nextRoot;
-    }
-}
-
 static void markRoots(CState *state)
 {
     // mark all values on the stack
@@ -285,8 +287,7 @@ static void markRoots(CState *state)
     for (int i = 0; i < ISTRING_MAX; i++)
         markObject(state, (CObj *)state->iStrings[i]);
 
-    // mark the user defined roots
-    markUserRoots(state);
+    markTable(state, &state->registry);
 
     for (int i = 0; i < COBJ_MAX; i++)
         markObject(state, (CObj *)state->protoObjects[i]);
@@ -323,44 +324,3 @@ COSMO_API void cosmoM_updateThreshhold(CState *state)
 {
     state->nextGC = state->allocatedBytes * HEAP_GROW_FACTOR;
 }
-
-COSMO_API void cosmoM_addRoot(CState *state, CObj *newRoot)
-{
-    // first, check and make sure this root doesn't already exist in the list
-    CObj *root = state->userRoots;
-    while (root != NULL) {
-        if (root == newRoot) // found in the list, abort
-            return;
-
-        root = root->nextRoot;
-    }
-
-    // adds root to userRoot linked list
-    newRoot->nextRoot = state->userRoots;
-    state->userRoots = newRoot;
-}
-
-COSMO_API void cosmoM_removeRoot(CState *state, CObj *oldRoot)
-{
-    CObj *prev = NULL;
-    CObj *root = state->userRoots;
-
-    // traverse the userRoot linked list
-    while (root != NULL) {
-        if (root == oldRoot) { // found root in list
-
-            // remove from the linked list
-            if (prev == NULL) {
-                state->userRoots = root->nextRoot;
-            } else {
-                prev->nextRoot = root->nextRoot;
-            }
-
-            root->nextRoot = NULL;
-            break;
-        }
-
-        prev = root;
-        root = root->nextRoot;
-    }
-}
diff --git a/src/cmem.h b/src/cmem.h
index 0063892..b617d76 100644
--- a/src/cmem.h
+++ b/src/cmem.h
@@ -67,13 +67,6 @@ COSMO_API bool cosmoM_checkGarbage(CState *state,
 COSMO_API void cosmoM_collectGarbage(CState *state);
 COSMO_API void cosmoM_updateThreshhold(CState *state);
 
-// lets the VM know you are holding a reference to a CObj and to not free it
-// NOTE: prefer to use the stack when possible
-COSMO_API void cosmoM_addRoot(CState *state, CObj *newRoot);
-
-// lets the VM know this root is no longer held in a reference and is able to be freed
-COSMO_API void cosmoM_removeRoot(CState *state, CObj *oldRoot);
-
 // wrapper for cosmoM_reallocate so we can track our memory usage
 static inline void *cosmoM_xmalloc(CState *state, size_t sz)
 {
diff --git a/src/cobj.c b/src/cobj.c
index 4f90673..ba47eda 100644
--- a/src/cobj.c
+++ b/src/cobj.c
@@ -31,7 +31,6 @@ CObj *cosmoO_allocateBase(CState *state, size_t sz, CObjType type)
     obj->next = state->objects;
     state->objects = obj;
 
-    obj->nextRoot = NULL;
 #ifdef GC_DEBUG
     printf("allocated %s %p\n", cosmoO_typeStr(obj), obj);
 #endif
@@ -51,9 +50,9 @@ void cosmoO_free(CState *state, CObj *obj)
         break;
     }
     case COBJ_OBJECT: {
-        CObjObject *objTbl = (CObjObject *)obj;
-        cosmoT_clearTable(state, &objTbl->tbl);
-        cosmoM_free(state, CObjObject, objTbl);
+        CObjObject *objObj = (CObjObject *)obj;
+        cosmoT_clearTable(state, &objObj->tbl);
+        cosmoM_free(state, CObjObject, objObj);
         break;
     }
     case COBJ_TABLE: {
@@ -492,6 +491,7 @@ void cosmoO_unlock(CObjObject *object)
     object->isLocked = false;
 }
 
+
 bool rawgetIString(CState *state, CObjObject *object, int flag, CValue *val)
 {
     if (readFlag(object->istringFlags, flag))
@@ -511,6 +511,8 @@ bool cosmoO_getIString(CState *state, CObjObject *object, int flag, CValue *val)
     CObjObject *obj = object;
 
     do {
+        printf("getting flag %d from obj: %p\n", flag, obj);
+        fflush(stdout);
         if (rawgetIString(state, obj, flag, val))
             return true;
     } while ((obj = obj->_obj.proto) != NULL); // sets obj to it's proto and compares it to NULL
diff --git a/src/cobj.h b/src/cobj.h
index 7f651b3..055d8fa 100644
--- a/src/cobj.h
+++ b/src/cobj.h
@@ -34,7 +34,6 @@ typedef int (*CosmoCFunction)(CState *state, int argCount, CValue *args);
 struct CObj
 {
     struct CObj *next;
-    struct CObj *nextRoot;    // for the root linked list
     struct CObjObject *proto; // protoobject, describes the behavior of the object
     CObjType type;
     bool isMarked; // for the GC
diff --git a/src/cstate.c b/src/cstate.c
index 81a084b..eb67366 100644
--- a/src/cstate.c
+++ b/src/cstate.c
@@ -42,7 +42,6 @@ CState *cosmoV_newState()
 
     // GC
     state->objects = NULL;
-    state->userRoots = NULL;
     state->grayStack.count = 0;
     state->grayStack.capacity = 2;
     state->grayStack.array = NULL;
@@ -62,11 +61,13 @@ CState *cosmoV_newState()
         state->iStrings[i] = NULL;
 
     cosmoT_initTable(state, &state->strings, 16); // init string table
+    cosmoT_initTable(state, &state->registry, 16);
 
     state->globals = cosmoO_newTable(state); // init global table
 
     // setup all strings used by the VM
     state->iStrings[ISTRING_INIT] = cosmoO_copyString(state, "__init", 6);
+    state->iStrings[ISTRING_GC] = cosmoO_copyString(state, "__gc", 4);
     state->iStrings[ISTRING_TOSTRING] = cosmoO_copyString(state, "__tostring", 10);
     state->iStrings[ISTRING_TONUMBER] = cosmoO_copyString(state, "__tonumber", 10);
     state->iStrings[ISTRING_INDEX] = cosmoO_copyString(state, "__index", 7);
@@ -120,6 +121,8 @@ void cosmoV_freeState(CState *state)
     // free our string table (the string table includes the internal VM strings)
     cosmoT_clearTable(state, &state->strings);
 
+    cosmoT_clearTable(state, &state->registry);
+
     // free our gray stack & finally free the state structure
     cosmoM_freeArray(state, CObj *, state->grayStack.array, state->grayStack.capacity);
 
@@ -133,7 +136,7 @@ void cosmoV_freeState(CState *state)
 }
 
 // expects 2*pairs values on the stack, each pair should consist of 1 key and 1 value
-void cosmoV_register(CState *state, int pairs)
+void cosmoV_addGlobals(CState *state, int pairs)
 {
     for (int i = 0; i < pairs; i++) {
         StkPtr key = cosmoV_getTop(state, 1);
@@ -146,6 +149,51 @@ void cosmoV_register(CState *state, int pairs)
     }
 }
 
+// expects 2*pairs values on the stack, each pair should consist of 1 key and 1 value
+void cosmoV_addRegistry(CState *state, int pairs)
+{
+    for (int i = 0; i < pairs; i++) {
+        StkPtr key = cosmoV_getTop(state, 1);
+        StkPtr val = cosmoV_getTop(state, 0);
+
+        CValue *oldVal = cosmoT_insert(state, &state->registry, *key);
+        *oldVal = *val;
+
+        cosmoV_setTop(state, 2); // pops the 2 values off the stack
+    }
+}
+
+// expects 1 key on the stack, pushes result
+void cosmoV_getRegistry(CState *state) {
+    CValue key = *cosmoV_pop(state);
+    CValue val;
+
+    if (!cosmoT_get(state, &state->registry, key, &val)) {
+        cosmoV_error(state, "failed to grab %s from registry", cosmoV_typeStr(key));
+    }
+
+    printf("got %s from registry - ", cosmoV_typeStr(val));
+    printValue(val);
+    printf("\n");
+    cosmoV_pushValue(state, val);
+}
+
+void cosmoV_setProto(CState *state) {
+    StkPtr objVal = cosmoV_getTop(state, 1);
+    StkPtr protoVal = cosmoV_getTop(state, 0);
+
+    if (!IS_REF(*objVal) || !IS_OBJECT(*protoVal)) {
+        cosmoV_error(state, "cannot set %s to proto of type %s", cosmoV_typeStr(*objVal), cosmoV_typeStr(*protoVal));
+    }
+
+    // actually set the protos
+    CObj *obj = cosmoV_readRef(*objVal);
+    CObjObject *proto = cosmoV_readObject(*protoVal);
+    obj->proto = proto;
+
+    cosmoV_setTop(state, 2);
+}
+
 void cosmoV_printStack(CState *state)
 {
     printf("==== [[ stack dump ]] ====\n");
diff --git a/src/cstate.h b/src/cstate.h
index a527ec8..f6d53eb 100644
--- a/src/cstate.h
+++ b/src/cstate.h
@@ -18,6 +18,7 @@ struct CCallFrame
 typedef enum IStringEnum
 {
     ISTRING_INIT,     // __init
+    ISTRING_GC,       // __gc
     ISTRING_TOSTRING, // __tostring
     ISTRING_TONUMBER, // __tonumber
     ISTRING_EQUAL,    // __equals
@@ -56,6 +57,7 @@ struct CState
     CObjObject *protoObjects[COBJ_MAX]; // proto object for each COBJ type [NULL = no default proto]
     CObjString *iStrings[ISTRING_MAX];  // strings used internally by the VM, eg. __init, __index
     CTable strings;
+    CTable registry;
     ArrayCObj grayStack; // keeps track of which objects *haven't yet* been traversed in our GC, but
                          // *have been* found
 
@@ -63,14 +65,12 @@ struct CState
     CObjTable *globals;
     CValue *top;     // top of the stack
     CObj *objects;   // tracks all of our allocated objects
-    CObj *userRoots; // user definable roots, this holds CObjs that should be considered "roots",
-                     // lets the VM know you are holding a reference to a CObj in your code
     CPanic *panic;
 
-    int freezeGC; // when > 0, GC events will be ignored (for internal use)
-    int frameCount;
     size_t allocatedBytes;
     size_t nextGC; // when allocatedBytes reaches this threshhold, trigger a GC event
+    int freezeGC; // when > 0, GC events will be ignored (for internal use)
+    int frameCount;
 };
 
 CPanic *cosmoV_newPanic(CState *state);
@@ -80,7 +80,16 @@ COSMO_API CState *cosmoV_newState();
 COSMO_API void cosmoV_freeState(CState *state);
 
 // expects 2*pairs values on the stack, each pair should consist of 1 key and 1 value
-COSMO_API void cosmoV_register(CState *state, int pairs);
+COSMO_API void cosmoV_addGlobals(CState *state, int pairs);
+
+// expects 2*pairs values on the stack, each pair should consist of 1 key and 1 value
+COSMO_API void cosmoV_addRegistry(CState *state, int pairs);
+
+// expects 1 key on the stack, pushes result
+COSMO_API void cosmoV_getRegistry(CState *state);
+
+// expects <object>->proto = <object> (2 total) to be on the stack
+COSMO_API void cosmoV_setProto(CState *state);
 
 COSMO_API void cosmoV_printStack(CState *state);
 
diff --git a/src/cvm.c b/src/cvm.c
index 7e91b04..875b52d 100644
--- a/src/cvm.c
+++ b/src/cvm.c
@@ -12,7 +12,7 @@
 
 #define cosmoV_protect(panic) setjmp(panic->jmp) == 0
 
-COSMO_API void cosmoV_pushFString(CState *state, const char *format, ...)
+void cosmoV_pushFString(CState *state, const char *format, ...)
 {
     va_list args;
     va_start(args, format);
@@ -21,7 +21,7 @@ COSMO_API void cosmoV_pushFString(CState *state, const char *format, ...)
 }
 
 // inserts val at state->top - indx - 1, moving everything else up
-COSMO_API void cosmo_insert(CState *state, int indx, CValue val)
+void cosmoV_insert(CState *state, int indx, CValue val)
 {
     StkPtr tmp = cosmoV_getTop(state, indx);
 
@@ -33,7 +33,7 @@ COSMO_API void cosmo_insert(CState *state, int indx, CValue val)
     state->top++;
 }
 
-COSMO_API bool cosmoV_undump(CState *state, cosmo_Reader reader, const void *ud)
+bool cosmoV_undump(CState *state, cosmo_Reader reader, const void *ud)
 {
     CObjFunction *func;
 
@@ -54,7 +54,7 @@ COSMO_API bool cosmoV_undump(CState *state, cosmo_Reader reader, const void *ud)
 
 // returns false if failed, error will be on the top of the stack. true if successful, closure will
 // be on the top of the stack
-COSMO_API bool cosmoV_compileString(CState *state, const char *src, const char *name)
+bool cosmoV_compileString(CState *state, const char *src, const char *name)
 {
     CObjFunction *func;
     CPanic *panic = cosmoV_newPanic(state);
@@ -77,7 +77,7 @@ COSMO_API bool cosmoV_compileString(CState *state, const char *src, const char *
     return false;
 }
 
-COSMO_API void cosmoV_printError(CState *state, CObjError *err)
+void cosmoV_printError(CState *state, CObjError *err)
 {
     // print stack trace
     for (int i = 0; i < err->frameCount; i++) {
@@ -439,7 +439,7 @@ static inline bool isFalsey(StkPtr val)
     return IS_NIL(*val) || (IS_BOOLEAN(*val) && !cosmoV_readBoolean(*val));
 }
 
-COSMO_API CObjObject *cosmoV_makeObject(CState *state, int pairs)
+CObjObject *cosmoV_makeObject(CState *state, int pairs)
 {
     StkPtr key, val;
     CObjObject *newObj = cosmoO_newObject(state);
@@ -460,7 +460,7 @@ COSMO_API CObjObject *cosmoV_makeObject(CState *state, int pairs)
     return newObj;
 }
 
-COSMO_API bool cosmoV_registerProtoObject(CState *state, CObjType objType, CObjObject *obj)
+bool cosmoV_registerProtoObject(CState *state, CObjType objType, CObjObject *obj)
 {
     bool replaced = state->protoObjects[objType] != NULL;
     state->protoObjects[objType] = obj;
@@ -469,7 +469,7 @@ COSMO_API bool cosmoV_registerProtoObject(CState *state, CObjType objType, CObjO
     CObj *curr = state->objects;
     while (curr != NULL) {
         // update the proto
-        if (curr->type == objType && curr->proto != NULL) {
+        if (curr != (CObj *)obj && curr->type == objType && curr->proto != NULL) {
             curr->proto = obj;
         }
         curr = curr->next;
@@ -478,7 +478,7 @@ COSMO_API bool cosmoV_registerProtoObject(CState *state, CObjType objType, CObjO
     return replaced;
 }
 
-COSMO_API void cosmoV_makeTable(CState *state, int pairs)
+void cosmoV_makeTable(CState *state, int pairs)
 {
     StkPtr key, val;
     CObjTable *newObj = cosmoO_newTable(state);
@@ -530,7 +530,7 @@ void cosmoV_rawset(CState *state, CObj *_obj, CValue key, CValue val)
     cosmoO_setRawObject(state, object, key, val, _obj);
 }
 
-COSMO_API void cosmoV_get(CState *state)
+void cosmoV_get(CState *state)
 {
     CValue val;
     StkPtr obj = cosmoV_getTop(state, 1); // object was pushed first
@@ -548,7 +548,7 @@ COSMO_API void cosmoV_get(CState *state)
 }
 
 // yes, this would technically make it possible to set fields of types other than <string>. go crazy
-COSMO_API void cosmoV_set(CState *state)
+void cosmoV_set(CState *state)
 {
     StkPtr obj = cosmoV_getTop(state, 2); // object was pushed first
     StkPtr key = cosmoV_getTop(state, 1); // then the key
@@ -564,7 +564,7 @@ COSMO_API void cosmoV_set(CState *state)
     cosmoV_setTop(state, 3);
 }
 
-COSMO_API void cosmoV_getMethod(CState *state, CObj *obj, CValue key, CValue *val)
+void cosmoV_getMethod(CState *state, CObj *obj, CValue key, CValue *val)
 {
     cosmoV_rawget(state, obj, key, val);
 
@@ -578,6 +578,19 @@ COSMO_API void cosmoV_getMethod(CState *state, CObj *obj, CValue key, CValue *va
     }
 }
 
+bool cosmoV_isValueUserType(CState *state, CValue val, int userType) {
+    if (!IS_OBJECT(val)) {
+        return false;
+    }
+
+    CObjObject *obj = cosmoV_readObject(val);
+    if (obj->userT != userType) {
+        return false;
+    }
+
+    return true;
+}
+
 int _tbl__next(CState *state, int nargs, CValue *args)
 {
     if (nargs != 1) {
@@ -836,7 +849,8 @@ int cosmoV_execute(CState *state)
 
                 CObj *obj = cosmoV_readRef(*temp);
                 CObjObject *proto = cosmoO_grabProto(obj);
-                CValue val; // to hold our value
+                CValue val = cosmoV_newNil();          // to hold our value
+
 
                 if (proto != NULL) {
                     // check for __index metamethod
@@ -907,7 +921,7 @@ int cosmoV_execute(CState *state)
             }
             CASE(OP_GETOBJECT) :
             {
-                CValue val;                            // to hold our value
+                CValue val = cosmoV_newNil();          // to hold our value
                 StkPtr temp = cosmoV_getTop(state, 0); // that should be the object
                 uint16_t ident = READUINT(frame);      // use for the key
 
@@ -925,7 +939,7 @@ int cosmoV_execute(CState *state)
             }
             CASE(OP_GETMETHOD) :
             {
-                CValue val;                            // to hold our value
+                CValue val = cosmoV_newNil();          // to hold our value
                 StkPtr temp = cosmoV_getTop(state, 0); // that should be the object
                 uint16_t ident = READUINT(frame);      // use for the key
 
diff --git a/src/cvm.h b/src/cvm.h
index d4bbada..4eac843 100644
--- a/src/cvm.h
+++ b/src/cvm.h
@@ -36,11 +36,11 @@ COSMO_API void cosmoV_pushFString(CState *state, const char *format, ...);
 COSMO_API void cosmoV_printError(CState *state, CObjError *err);
 COSMO_API void cosmoV_throw(CState *state);
 COSMO_API void cosmoV_error(CState *state, const char *format, ...);
-COSMO_API void cosmo_insert(CState *state, int indx, CValue val);
+COSMO_API void cosmoV_insert(CState *state, int indx, CValue val);
 
 /*
     Sets the default proto objects for the passed objType. Also walks through the object heap and
-   updates protos for the passed objType if that CObj* has no proto.
+    updates protos for the passed objType if that CObj* has no proto.
 
     returns true if replacing a previously registered proto object for this type
 */
@@ -72,13 +72,16 @@ COSMO_API bool cosmoV_undump(CState *state, cosmo_Reader reader, const void *ud)
 COSMO_API void cosmoV_get(CState *state);
 
 /*
-    expects object to be pushed, then the key, and finally the new value. pops the key & object
+    expects object to be pushed, then the key, and finally the new value. pops the object, key & value
 */
 COSMO_API void cosmoV_set(CState *state);
 
 // wraps the closure into a CObjMethod, so the function is called as an invoked method
 COSMO_API void cosmoV_getMethod(CState *state, CObj *obj, CValue key, CValue *val);
 
+// check if the value at the top of the stack is a <obj> user type
+COSMO_API bool cosmoV_isValueUserType(CState *state, CValue val, int userType);
+
 // nice to have wrappers
 
 // pushes a raw CValue to the stack, might throw an error if the stack is overflowed (with the