diff --git a/eventlet/api.py b/eventlet/api.py
index 82df92e..af65cff 100644
--- a/eventlet/api.py
+++ b/eventlet/api.py
@@ -31,7 +31,7 @@ import inspect
 import traceback
 
 from eventlet.support import greenlet
-from eventlet import greenlib, tls
+from eventlet import tls
 
 __all__ = [
     'call_after', 'exc_after', 'getcurrent', 'get_default_hub', 'get_hub',
@@ -135,15 +135,15 @@ def trampoline(fd, read=None, write=None, timeout=None, timeout_exc=TimeoutError
     """
     t = None
     hub = get_hub()
-    self = greenlet.getcurrent()
-    assert hub.greenlet is not self, 'do not call blocking functions from the mainloop'
+    current = greenlet.getcurrent()
+    assert hub.greenlet is not current, 'do not call blocking functions from the mainloop'
     fileno = getattr(fd, 'fileno', lambda: fd)()
     def _do_close(_d, error=None):
-        greenlib.switch(self, exc=getattr(error, 'value', None)) # convert to socket.error
+        current.throw(getattr(error, 'value', None)) # convert to socket.error
     def _do_timeout():
-        greenlib.switch(self, exc=timeout_exc())
+        current.throw(timeout_exc())
     def cb(d):
-        greenlib.switch(self)
+        current.switch()
         # with TwistedHub, descriptor actually an object (socket_rwdescriptor) which stores
         # this callback. If this callback stores a reference to the socket instance (fd)
         # then descriptor has a reference to that instance. This makes socket not collected
@@ -173,10 +173,10 @@ def get_fileno(obj):
         return f()
 
 def select(read_list, write_list, error_list, timeout=None):
-    self = get_hub()
+    hub = get_hub()
     t = None
     current = greenlet.getcurrent()
-    assert self.greenlet is not current, 'do not call blocking functions from the mainloop'
+    assert hub.greenlet is not current, 'do not call blocking functions from the mainloop'
     ds = {}
     for r in read_list:
         ds[get_fileno(r)] = {'read' : r}
@@ -189,33 +189,33 @@ def select(read_list, write_list, error_list, timeout=None):
 
     def on_read(d):
         original = ds[get_fileno(d)]['read']
-        greenlib.switch(current, ([original], [], []))
+        current.switch(([original], [], []))
 
     def on_write(d):
         original = ds[get_fileno(d)]['write']
-        greenlib.switch(current, ([], [original], []))
+        current.switch(([], [original], []))
 
     def on_error(d, _err=None):
         original = ds[get_fileno(d)]['error']
-        greenlib.switch(current, ([], [], [original]))
+        current.switch(([], [], [original]))
 
     def on_timeout():
-        greenlib.switch(current, ([], [], []))
+        current.switch(([], [], []))
 
     if timeout is not None:
-        t = self.schedule_call(timeout, on_timeout)
+        t = hub.schedule_call(timeout, on_timeout)
     try:
         for k, v in ds.iteritems():
-            d = self.add_descriptor(k,
-                                    v.get('read') is not None and on_read,
-                                    v.get('write') is not None and on_write,
-                                    v.get('error') is not None and on_error)
+            d = hub.add_descriptor(k,
+                                   v.get('read') is not None and on_read,
+                                   v.get('write') is not None and on_write,
+                                   v.get('error') is not None and on_error)
             descriptors.append(d)
         try:
-            return self.switch()
+            return hub.switch()
         finally:
             for d in descriptors:
-                self.remove_descriptor(d)
+                hub.remove_descriptor(d)
     finally:
         if t is not None:
             t.cancel()
@@ -223,7 +223,7 @@ def select(read_list, write_list, error_list, timeout=None):
 
 def _spawn_startup(cb, args, kw, cancel=None):
     try:
-        greenlib.switch(greenlet.getcurrent().parent)
+        greenlet.getcurrent().parent.switch()
         cancel = None
     finally:
         if cancel is not None:
@@ -232,7 +232,25 @@ def _spawn_startup(cb, args, kw, cancel=None):
 
 def _spawn(g):
     g.parent = greenlet.getcurrent()
-    greenlib.switch(g)
+    g.switch()
+
+
+class CancellingTimersGreenlet(greenlet.greenlet):
+
+    def __init__(self, run=None, parent=None, hub=None):
+        self._run = run
+        if parent is None:
+            parent = greenlet.getcurrent()
+        if hub is None:
+            hub = get_hub()
+        self.hub = hub
+        greenlet.greenlet.__init__(self, None, parent)
+
+    def run(self, *args, **kwargs):
+        try:
+            return self._run(*args, **kwargs)
+        finally:
+            self.hub.cancel_timers(self, quiet=True)
 
 
 def spawn(function, *args, **kwds):
@@ -251,17 +269,18 @@ def spawn(function, *args, **kwds):
     """
     # killable
     t = None
-    g = greenlib.tracked_greenlet()
-    t = get_hub().schedule_call(0, _spawn, g)
-    greenlib.switch(g, (_spawn_startup, function, args, kwds, t.cancel))
+    g = CancellingTimersGreenlet(_spawn_startup)
+    t = get_hub().schedule_call_global(0, _spawn, g)
+    g.switch(function, args, kwds, t.cancel)
     return g
 
 def kill(g):
-    get_hub().schedule_call(0, greenlib.kill, g)
-    sleep(0) 
+    get_hub().schedule_call(0, g.throw)
+    sleep(0)
 
-def call_after(seconds, function, *args, **kwds):
+def call_after_global(seconds, function, *args, **kwds):
     """Schedule *function* to be called after *seconds* have elapsed.
+    The function will be scheduled even if the current greenlet has exited.
     
     *seconds* may be specified as an integer, or a float if fractional seconds
     are desired. The *function* will be called with the given *args* and
@@ -272,12 +291,35 @@ def call_after(seconds, function, *args, **kwds):
     """
     # cancellable
     def startup():
-        g = greenlib.tracked_greenlet()
-        greenlib.switch(g, (_spawn_startup, function, args, kwds))
-        greenlib.switch(g)
-    return get_hub().schedule_call(seconds, startup)
+        g = CancellingTimersGreenlet(_spawn_startup)
+        g.switch(function, args, kwds)
+        g.switch()
+    t = get_hub().schedule_call_global(seconds, startup)
+    return t
 
 
+def call_after_local(seconds, function, *args, **kwds):
+    """Schedule *function* to be called after *seconds* have elapsed.
+    The function will NOT be called if the current greenlet has exited.
+    
+    *seconds* may be specified as an integer, or a float if fractional seconds
+    are desired. The *function* will be called with the given *args* and
+    keyword arguments *kwds*, and will be executed within the main loop's
+    coroutine.
+
+    Its return value is discarded. Any uncaught exception will be logged.
+    """
+    # cancellable
+    def startup():
+        g = CancellingTimersGreenlet(_spawn_startup)
+        g.switch(function, args, kwds)
+        g.switch()
+    t = get_hub().schedule_call_local(seconds, startup)
+    return t
+
+# for compatibility with original eventlet API
+call_after = call_after_local
+
 def with_timeout(seconds, func, *args, **kwds):
     """Wrap a call to some (yielding) function with a timeout; if the called
     function fails to return before the timeout, cancel it and return a flag
@@ -422,15 +464,13 @@ def sleep(seconds=0):
     """
     hub = get_hub()
     assert hub.greenlet is not greenlet.getcurrent(), 'do not call blocking functions from the mainloop'
-    timer = hub.schedule_call(seconds, greenlib.switch, greenlet.getcurrent())
+    timer = hub.schedule_call(seconds, greenlet.getcurrent().switch)
     try:
         hub.switch()
     finally:
         timer.cancel()
 
 
-switch = greenlib.switch
-local_dict = greenlib.greenlet_dict
 getcurrent = greenlet.getcurrent
 GreenletExit = greenlet.GreenletExit
 
diff --git a/eventlet/channel.py b/eventlet/channel.py
index a8be44e..32be5ae 100644
--- a/eventlet/channel.py
+++ b/eventlet/channel.py
@@ -25,7 +25,7 @@ THE SOFTWARE.
 
 import collections
 
-from eventlet import api, greenlib
+from eventlet import api
 from eventlet.support import greenlet
 
 __all__ = ['channel']
@@ -49,8 +49,13 @@ class channel(object):
     def _tasklet_loop(self):
         deque = self.deque = collections.deque()
         hub = api.get_hub()
-        switch = greenlib.switch
-        direction, caller, args = switch()
+        current = greenlet.getcurrent()
+        def switch(g, value=None, exc=None):
+            if exc is None:
+                return g.switch(value)
+            else:
+                return g.throw(exc)
+        direction, caller, args = switch(current.parent or current)
         try:
             while True:
                 if direction == -1:
@@ -80,12 +85,12 @@ class channel(object):
         try:
             t = self._tasklet
         except AttributeError:
-            t = self._tasklet = greenlib.tracked_greenlet()
-            greenlib.switch(t, (self._tasklet_loop,))
+            t = self._tasklet = greenlet.greenlet(self._tasklet_loop)
+            t.switch()
         if args:
-            return greenlib.switch(t, (1, greenlet.getcurrent(), args))
+            return t.switch((1, greenlet.getcurrent(), args))
         else:
-            return greenlib.switch(t, (-1, greenlet.getcurrent(), args))
+            return t.switch((-1, greenlet.getcurrent(), args))
         
     def receive(self):
         return self._send_tasklet()
diff --git a/eventlet/coros.py b/eventlet/coros.py
index e1b77b4..da6d690 100644
--- a/eventlet/coros.py
+++ b/eventlet/coros.py
@@ -31,7 +31,6 @@ import traceback
 from eventlet import api
 from eventlet import channel
 from eventlet import pools
-from eventlet import greenlib
 
 
 try:
@@ -182,7 +181,7 @@ class event(object):
         if waiter in self._waiters:
             del self._waiters[waiter]
             api.get_hub().schedule_call(
-                0, greenlib.switch, waiter, None, Cancelled())
+                0, waiter.throw, Cancelled())
 
     def send(self, result=None, exc=None):
         """Makes arrangements for the waiters to be woken with the
@@ -215,8 +214,7 @@ class event(object):
         self._exc = exc
         hub = api.get_hub()
         for waiter in self._waiters:
-            hub.schedule_call(0, greenlib.switch, waiter, self._result)
-
+            hub.schedule_call(0, waiter.switch, self._result)
 
 class semaphore(object):
     """Classic semaphore implemented with a counter and an event.
diff --git a/eventlet/green/thread.py b/eventlet/green/thread.py
index 31f220b..cd7176a 100644
--- a/eventlet/green/thread.py
+++ b/eventlet/green/thread.py
@@ -1,16 +1,21 @@
 """implements standard module 'thread' with greenlets"""
 from __future__ import absolute_import
 import thread as thread_module
-from eventlet.greenlib import greenlet_id as get_ident
 from eventlet.support import greenlet
 from eventlet.api import spawn
 from eventlet.coros import semaphore as LockType
 
 error = thread_module.error
 
+def get_ident(gr=None):
+    if gr is None:
+        return id(greenlet.getcurrent())
+    else:
+        return id(gr)
+
 def start_new_thread(function, args=(), kwargs={}):
     g = spawn(function, *args, **kwargs)
-    return get_ident(g) or 0 # XXX 0 only for main greenlet, None for the rest untracked
+    return get_ident(g)
 
 def allocate_lock():
     return LockType(1)
diff --git a/eventlet/hubs/hub.py b/eventlet/hubs/hub.py
index 4e93000..9109ecb 100644
--- a/eventlet/hubs/hub.py
+++ b/eventlet/hubs/hub.py
@@ -30,8 +30,6 @@ import traceback
 import time
 
 from eventlet.support import greenlet
-
-from eventlet import greenlib
 from eventlet.timer import Timer
 
 _g_debug = True
@@ -49,7 +47,7 @@ class BaseHub(object):
         self.waiters_by_greenlet = {}
 
         self.clock = clock
-        self.greenlet = None
+        self.greenlet = greenlet.greenlet(self.run)
         self.stopping = False
         self.running = False
         self.timers = []
@@ -106,7 +104,7 @@ class BaseHub(object):
         fileno = self.waiters_by_greenlet.pop(gr, None)
         if fileno is not None:
             self.remove_descriptor(fileno)
-        greenlib.switch(gr, None, exception_object)
+        gr.throw(exception_object)
 
     def exc_descriptor(self, fileno):
         exc = self.excs.get(fileno)
@@ -122,16 +120,13 @@ class BaseHub(object):
             self.switch()
 
     def switch(self):
-        if not self.greenlet:
-            self.greenlet = greenlib.tracked_greenlet()
-            args = ((self.run,),)
-        else:
-            args = ()
+        if self.greenlet.dead:
+            self.greenlet = greenlet.greenlet(self.run)
         try:
             greenlet.getcurrent().parent = self.greenlet
         except ValueError:
             pass
-        return greenlib.switch(self.greenlet, *args)
+        return self.greenlet.switch()
 
     def squelch_exception(self, fileno, exc_info):
         traceback.print_exception(*exc_info)
diff --git a/eventlet/hubs/libev.py b/eventlet/hubs/libev.py
index 3baf741..d839ecd 100644
--- a/eventlet/hubs/libev.py
+++ b/eventlet/hubs/libev.py
@@ -29,7 +29,6 @@ import errno
 import traceback
 import time
 
-from eventlet import greenlib
 from eventlet.timer import Timer
 from eventlet.hubs import hub
 
diff --git a/eventlet/hubs/nginx.py b/eventlet/hubs/nginx.py
index 3d5a905..0914df0 100644
--- a/eventlet/hubs/nginx.py
+++ b/eventlet/hubs/nginx.py
@@ -36,7 +36,6 @@ if mydir not in sys.path:
 
 
 from eventlet import api
-from eventlet import greenlib
 from eventlet import httpc
 from eventlet.hubs import hub
 from eventlet import util
@@ -112,7 +111,7 @@ class Hub(hub.BaseHub):
             result = to_call[0](to_call[1])
             del self.to_call
             return result
-        greenlib.switch(self.current_application, self.poll(int(seconds*1000)))
+        self.current_application.switch(self.poll(int(seconds*1000)))
 
     def application(self, env, start_response):
         print "ENV",env
@@ -151,8 +150,8 @@ class Hub(hub.BaseHub):
                         yield x
                 return
             result = self.switch()
-            if not isinstance(result, tuple):
-                result = (result, None) ## TODO Fix greenlib's return values
+            #if not isinstance(result, tuple):
+            #    result = (result, None) ## TODO Fix greenlib's return values
 
 
 def application(env, start_response):
diff --git a/eventlet/hubs/poll.py b/eventlet/hubs/poll.py
index 981c153..a6ec709 100644
--- a/eventlet/hubs/poll.py
+++ b/eventlet/hubs/poll.py
@@ -31,7 +31,6 @@ import traceback
 from time import sleep
 import time
 
-from eventlet import greenlib
 from eventlet.hubs import hub
 
 EXC_MASK = select.POLLERR | select.POLLHUP | select.POLLNVAL
diff --git a/eventlet/hubs/twistedr.py b/eventlet/hubs/twistedr.py
index 29073d2..22ad203 100644
--- a/eventlet/hubs/twistedr.py
+++ b/eventlet/hubs/twistedr.py
@@ -3,7 +3,6 @@ import threading
 import weakref
 from twisted.internet.base import DelayedCall as TwistedDelayedCall
 from eventlet.hubs.hub import _g_debug
-from eventlet import greenlib
 from eventlet.support.greenlet import greenlet
 
 import traceback
@@ -78,7 +77,7 @@ class BaseTwistedHub(object):
            greenlet.getcurrent().parent = self.greenlet
         except ValueError, ex:
            pass
-        return greenlib.switch(self.greenlet)
+        return self.greenlet.switch()
 
     def stop(self):
         from twisted.internet import reactor
@@ -105,7 +104,7 @@ class BaseTwistedHub(object):
         fileno = self.waiters_by_greenlet.pop(gr, None)
         if fileno is not None:
             self.remove_descriptor(fileno)
-        greenlib.switch(gr, None, exception_object)
+        gr.throw(exception_object)
 
     # required by GreenSocket
     def exc_descriptor(self, _fileno):
@@ -212,7 +211,6 @@ class BaseTwistedHub(object):
         return len(reactor.getDelayedCalls())
 
 
-
 class TwistedHub(BaseTwistedHub):
     # wrapper around reactor that runs reactor's main loop in a separate greenlet.
     # whenever you need to wait, i.e. inside a call that must appear
@@ -235,19 +233,17 @@ class TwistedHub(BaseTwistedHub):
         assert Hub.state==0, ('This hub can only be instantiated once', Hub.state)
         Hub.state = 1
         make_twisted_threadpool_daemonic() # otherwise the program would hang after the main greenlet exited
-        BaseTwistedHub.__init__(self, None)
+        g = greenlet(self.run)
+        BaseTwistedHub.__init__(self, g)
 
     def switch(self):
-        if not self.greenlet:
-            self.greenlet = greenlib.tracked_greenlet()
-            args = ((self.run,),)
-        else:
-            args = ()
+        if self.greenlet.dead:
+            self.greenlet = greenlet(self.run)
         try:
            greenlet.getcurrent().parent = self.greenlet
         except ValueError, ex:
            pass
-        return greenlib.switch(self.greenlet, *args)
+        return self.greenlet.switch()
 
     def run(self, installSignalHandlers=None):
         if installSignalHandlers is None:
diff --git a/eventlet/twistedutil/__init__.py b/eventlet/twistedutil/__init__.py
index 1441b55..43d01e2 100644
--- a/eventlet/twistedutil/__init__.py
+++ b/eventlet/twistedutil/__init__.py
@@ -1,18 +1,17 @@
 from twisted.internet import defer
 from twisted.python import failure
 from eventlet.support.greenlet import greenlet
-from eventlet import greenlib
 from eventlet.api import get_hub, spawn
 
 def block_on(deferred):
     cur = [greenlet.getcurrent()]
     def cb(value):
         if cur:
-            greenlib.switch(cur[0], value)
+            cur[0].switch(value)
         return value
     def eb(err):
         if cur:
-            greenlib.switch(cur[0], exc=(err.type, err.value, err.tb))
+            err.throwExceptionIntoGenerator(cur[0])
         return err
     deferred.addCallback(cb)
     deferred.addErrback(eb)
@@ -41,7 +40,10 @@ def callInGreenThread(func, *args, **kwargs):
 
 if __name__=='__main__':
     import sys
-    num = int(sys.argv[1])
+    try:
+        num = int(sys.argv[1])
+    except:
+        sys.exit('Supply number of test as an argument, 0, 1, 2 or 3')
     from twisted.internet import reactor
     def test():
         print block_on(reactor.resolver.getHostByName('www.google.com'))
@@ -51,7 +53,9 @@ if __name__=='__main__':
     elif num==1:
         spawn(test)
         from eventlet.api import sleep
+        print 'sleeping..'
         sleep(5)
+        print 'done sleeping..'
     elif num==2:
         from eventlet.twistedutil import join_reactor
         spawn(test)