diff --git a/mps/code/thlii4.c b/mps/code/thlii4.c
deleted file mode 100644
index 4f96e9c5fb1..00000000000
--- a/mps/code/thlii4.c
+++ /dev/null
@@ -1,346 +0,0 @@
-/* thlii4.c: Threads Manager for Intel x86 systems with LinuxThreads
- *
- *  $Id$
- *  Copyright (c) 2001 Ravenbrook Limited.  See end of file for license.
- *
- * .purpose: This is a pthreads implementation of the threads manager.
- * This implements <code/th.h>.
- *
- * .design: See <design/thread-manager/>.
- *
- * .thread.id: The thread id is used to identify the current thread.
- *
- * ASSUMPTIONS
- *
- * .error.resume: PThreadextResume is assumed to succeed unless the thread
- * has been destroyed.
- * .error.suspend: PThreadextSuspend is assumed to succeed unless the thread
- * has been destroyed. In this case, the suspend context is set to NULL;
- *
- * .stack.full-descend:  assumes full descending stack.
- * i.e. stack pointer points to the last allocated location;
- * stack grows downwards.
- *
- * .stack.below-bottom: it's legal for the stack pointer to be at a
- * higher address than the registered bottom of stack. This might
- * happen if the stack of another thread doesn't contain any frames
- * belonging to the client language. In this case, the stack should
- * not be scanned.
- *
- * .stack.align: assume roots on the stack are always word-aligned,
- * but don't assume that the stack pointer is necessarily
- * word-aligned at the time of reading the context of another thread.
- *
- * .sp: The stack pointer in the context is ESP.
- * .context.regroots: The root regs are EDI, ESI, EBX, EDX, ECX, EAX are
- * assumed to be recorded in the context at pointer-aligned boundaries.
- */
-
-#include "prmcix.h"
-#include "mpm.h"
-
-#if !defined(MPS_OS_LI) || !defined(MPS_ARCH_I4)
-#error "Compiling thlii4 when MPS_OS_LI or MPS_ARCH_I4 not defined."
-#endif
-
-#include <pthread.h>
-#include "pthrdext.h"
-
-SRCID(thlii4, "$Id$");
-
-
-/* ThreadStruct -- thread desriptor */
-
-typedef struct ThreadStruct {    /* PThreads thread structure */
-  Sig sig;                       /* <design/sig/> */
-  Serial serial;                 /* from arena->threadSerial */
-  Arena arena;                   /* owning arena */
-  RingStruct arenaRing;          /* threads attached to arena */
-  PThreadextStruct thrextStruct; /* PThreads extension */
-  pthread_t id;                  /* Pthread object of thread */
-  MutatorFaultContext mfc;       /* Context if thread is suspended */
-} ThreadStruct;
-
-
-/* ThreadCheck -- check a thread */
-
-Bool ThreadCheck(Thread thread)
-{
-  CHECKS(Thread, thread);
-  CHECKU(Arena, thread->arena);
-  CHECKL(thread->serial < thread->arena->threadSerial);
-  CHECKL(RingCheck(&thread->arenaRing));
-  CHECKD(PThreadext, &thread->thrextStruct);
-  return TRUE;
-}
-
-Bool ThreadCheckSimple(Thread thread)
-{
-  CHECKS(Thread, thread);
-  return TRUE;
-}
-
-
-/* ThreadRegister -- register a thread with an arena */
-
-Res ThreadRegister(Thread *threadReturn, Arena arena)
-{
-  Res res;
-  Thread thread;
-  void *p;
-
-  AVER(threadReturn != NULL);
-  AVERT(Arena, arena);
-
-  res = ControlAlloc(&p, arena, sizeof(ThreadStruct),
-                     /* withReservoirPermit */ FALSE);
-  if(res != ResOK)
-    return res;
-  thread = (Thread)p;
-
-  thread->id = pthread_self();
-
-  RingInit(&thread->arenaRing);
-
-  thread->sig = ThreadSig;
-  thread->serial = arena->threadSerial;
-  ++arena->threadSerial;
-  thread->arena = arena;
-  thread->mfc = NULL;
-
-  PThreadextInit(&thread->thrextStruct, thread->id);
-
-  AVERT(Thread, thread);
-
-  RingAppend(ArenaThreadRing(arena), &thread->arenaRing);
-
-  *threadReturn = thread;
-  return ResOK;
-}
-
-
-/* ThreadDeregister -- deregister a thread from an arena */
-
-void ThreadDeregister(Thread thread, Arena arena)
-{
-  AVERT(Thread, thread);
-  AVERT(Arena, arena);
-
-  RingRemove(&thread->arenaRing);
-
-  thread->sig = SigInvalid;
-
-  RingFinish(&thread->arenaRing);
-
-  PThreadextFinish(&thread->thrextStruct);
-
-  ControlFree(arena, thread, sizeof(ThreadStruct));
-}
-
-
-/*  mapThreadRing -- map over threads on ring calling a function on each one
- *                   except the current thread
- */
-
-static void mapThreadRing(Ring threadRing, void (*func)(Thread))
-{
-  Ring node, next;
-  pthread_t self;
-
-  AVERT(Ring, threadRing);
-
-  self = pthread_self();
-  RING_FOR(node, threadRing, next) {
-    Thread thread = RING_ELT(Thread, arenaRing, node);
-    AVERT(Thread, thread);
-    if(! pthread_equal(self, thread->id)) /* .thread.id */
-      (*func)(thread);
-  }
-}
-
-
-/* ThreadRingSuspend -- suspend all threads on a ring, expect the current one */
-
-
-static void threadSuspend(Thread thread)
-{
-  /* .error.suspend */
-  /* In the error case (PThreadextSuspend returning ResFAIL), we */
-  /* assume the thread has been destroyed. */
-  /* In which case we simply continue. */
-  Res res;
-  res = PThreadextSuspend(&thread->thrextStruct, &thread->mfc);
-  if(res != ResOK)
-    thread->mfc = NULL;
-}
-
-
-
-void ThreadRingSuspend(Ring threadRing)
-{
-  mapThreadRing(threadRing, threadSuspend);
-}
-
-
-/* ThreadRingResume -- resume all threads on a ring (expect the current one) */
-
-
-static void threadResume(Thread thread)
-{
-  /* .error.resume */
-  /* If the previous suspend failed (thread->mfc == NULL), */
-  /* or in the error case (PThreadextResume returning ResFAIL), */
-  /* assume the thread has been destroyed. */
-  /* In which case we simply continue. */
-  if(thread->mfc != NULL) {
-    (void)PThreadextResume(&thread->thrextStruct);
-    thread->mfc = NULL;
-  }
-}
-
-void ThreadRingResume(Ring threadRing)
-{
-  mapThreadRing(threadRing, threadResume);
-}
-
-
-/* ThreadRingThread -- return the thread at the given ring element */
-
-Thread ThreadRingThread(Ring threadRing)
-{
-  Thread thread;
-  AVERT(Ring, threadRing);
-  thread = RING_ELT(Thread, arenaRing, threadRing);
-  AVERT(Thread, thread);
-  return thread;
-}
-
-
-/* ThreadArena -- get the arena of a thread
- *
- * Must be thread-safe.  See <design/interface-c/#thread-safety>.
- */
-
-Arena ThreadArena(Thread thread)
-{
-  /* Can't check thread as that would not be thread-safe. */
-  return thread->arena;
-}
-
-
-/* ThreadScan -- scan the state of a thread (stack and regs) */
-
-Res ThreadScan(ScanState ss, Thread thread, void *stackBot)
-{
-  pthread_t self;
-  Res res;
-
-  AVERT(Thread, thread);
-  self = pthread_self();
-  if(pthread_equal(self, thread->id)) {
-    /* scan this thread's stack */
-    res = StackScan(ss, stackBot);
-    if(res != ResOK)
-      return res;
-  } else {
-    MutatorFaultContext mfc;
-    Addr *stackBase, *stackLimit, stackPtr;
-    mcontext_t *mc;
-    mfc = thread->mfc;
-    if(mfc == NULL) {
-      /* .error.suspend */
-      /* We assume that the thread must have been destroyed. */
-      /* We ignore the situation by returning immediately. */
-      return ResOK;
-    }
-
-    stackPtr  = (Addr)mfc->ucontext->uc_stack.ss_sp;   /* .i3.sp */
-    /* .stack.align */
-    stackBase  = (Addr *)AddrAlignUp(stackPtr, sizeof(Addr));
-    stackLimit = (Addr *)stackBot;
-    if (stackBase >= stackLimit)
-      return ResOK;    /* .stack.below-bottom */
-
-    /* scan stack inclusive of current sp and exclusive of
-     * stackBot (.stack.full-descend)
-     */
-    res = TraceScanAreaTagged(ss, stackBase, stackLimit);
-    if(res != ResOK)
-      return res;
-
-    /* (.context.regroots)
-     * This scans the root registers (.context.regroots).  It also
-     * unecessarily scans the rest of the context.  The optimisation
-     * to scan only relevent parts would be machine dependent.
-     */
-    mc = &mfc->ucontext->uc_mcontext;
-    res = TraceScanAreaTagged(ss, (Addr *)mc,
-           (Addr *)((char *)mc + sizeof(*mc)));
-    if(res != ResOK)
-      return res;
-  }
-
-  return ResOK;
-}
-
-
-/* ThreadDescribe -- describe a thread */
-
-Res ThreadDescribe(Thread thread, mps_lib_FILE *stream)
-{
-  Res res;
-
-  res = WriteF(stream,
-               "Thread $P ($U) {\n", (WriteFP)thread, (WriteFU)thread->serial,
-               "  arena $P ($U)\n",
-               (WriteFP)thread->arena, (WriteFU)thread->arena->serial,
-               "  id $U\n",          (WriteFU)thread->id,
-               "} Thread $P ($U)\n", (WriteFP)thread, (WriteFU)thread->serial,
-               NULL);
-  if(res != ResOK)
-    return res;
-
-  return ResOK;
-}
-
-
-/* C. COPYRIGHT AND LICENSE
- *
- * Copyright (C) 2001-2002 Ravenbrook Limited <http://www.ravenbrook.com/>.
- * All rights reserved.  This is an open source license.  Contact
- * Ravenbrook for commercial licensing options.
- * 
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- * 
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 
- * 3. Redistributions in any form must be accompanied by information on how
- * to obtain complete source code for this software and any accompanying
- * software that uses this software.  The source code must either be
- * included in the distribution or be available for no more than the cost
- * of distribution plus a nominal fee, and must be freely redistributable
- * under reasonable conditions.  For an executable file, complete source
- * code means the source code for all modules it contains. It does not
- * include source code for modules or files that typically accompany the
- * major components of the operating system on which the executable file
- * runs.
- * 
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
- * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
- * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
- * PURPOSE, OR NON-INFRINGEMENT, ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT HOLDERS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
- * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
- * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */