diff --git a/gfx/public/nsDeviceContext.h b/gfx/public/nsDeviceContext.h
index 099e419fd460..0d8c40280553 100644
--- a/gfx/public/nsDeviceContext.h
+++ b/gfx/public/nsDeviceContext.h
@@ -45,6 +45,8 @@
 #include "nsCOMPtr.h"
 #include "nsIAtom.h"
 #include "nsVoidArray.h"
+#include "nsIObserver.h"
+#include "nsIObserverService.h"
 
 class nsIImageRequest;
 class nsHashtable;
@@ -59,6 +61,9 @@ public:
   NS_IMETHOD GetDeviceContext(nsIDeviceContext *&aContext) const;
   NS_IMETHOD GetMetricsFor(const nsFont& aFont, nsIAtom* aLangGroup,
                            nsIFontMetrics *&aMetrics);
+
+  nsresult   FontMetricsDeleted(const nsIFontMetrics* aFontMetrics);
+  nsresult   Compact();
   nsresult   Flush();
   /* printer device context classes may create their own
    * subclasses of nsFontCache (and override this method) and override 
@@ -72,12 +77,14 @@ protected:
                               // ownership is implied. MMP.
 };
 
-class NS_GFX DeviceContextImpl : public nsIDeviceContext
+class NS_GFX DeviceContextImpl : public nsIDeviceContext,
+                                 public nsIObserver
 {
 public:
   DeviceContextImpl();
 
   NS_DECL_ISUPPORTS
+  NS_DECL_NSIOBSERVER
 
   NS_IMETHOD  Init(nsNativeWidget aWidget);
 
@@ -119,7 +126,7 @@ public:
                               PRBool& aAliased);
 
   NS_IMETHOD CreateFontCache();
-
+  NS_IMETHOD FontMetricsDeleted(const nsIFontMetrics* aFontMetrics);
   NS_IMETHOD FlushFontCache(void);
 
   NS_IMETHOD GetDepth(PRUint32& aDepth);
diff --git a/gfx/public/nsIDeviceContext.h b/gfx/public/nsIDeviceContext.h
index 642c23c232a7..42e7978f2952 100644
--- a/gfx/public/nsIDeviceContext.h
+++ b/gfx/public/nsIDeviceContext.h
@@ -338,6 +338,12 @@ public:
   NS_IMETHOD GetLocalFontName(const nsString& aFaceName, nsString& aLocalName,
                               PRBool& aAliased) = 0;
 
+  /**
+   * Notification when a font metrics instance created for this device is
+   * about to be deleted
+   */
+  NS_IMETHOD FontMetricsDeleted(const nsIFontMetrics* aFontMetrics) = 0;
+
   /**
    * Attempt to free up resoruces by flushing out any fonts no longer
    * referenced by anything other than the font cache itself.
diff --git a/gfx/src/beos/nsFontMetricsBeOS.cpp b/gfx/src/beos/nsFontMetricsBeOS.cpp
index 104ce05654d5..dedb8dbcd449 100644
--- a/gfx/src/beos/nsFontMetricsBeOS.cpp
+++ b/gfx/src/beos/nsFontMetricsBeOS.cpp
@@ -66,6 +66,10 @@ nsFontMetricsBeOS::~nsFontMetricsBeOS()
     delete mFont;
     mFont = nsnull;
   }
+  if (mDeviceContext) {
+    mDeviceContext->FontMetricsDeleted(this);
+    mDeviceContext = nsnull;
+  }
 }
  
 NS_IMPL_ISUPPORTS1(nsFontMetricsBeOS, nsIFontMetrics) 
@@ -94,6 +98,7 @@ NS_IMETHODIMP nsFontMetricsBeOS::Init(const nsFont& aFont, nsIAtom* aLangGroup,
 
   nsAutoString  firstFace;
   mLangGroup = aLangGroup;
+  mDeviceContext = aContext;
   if (NS_OK != aContext->FirstExistingFont(aFont, firstFace)) {
     aFont.GetFirstFamily(firstFace);
   }
@@ -166,6 +171,7 @@ NS_IMETHODIMP nsFontMetricsBeOS::Init(const nsFont& aFont, nsIAtom* aLangGroup,
 
 NS_IMETHODIMP  nsFontMetricsBeOS::Destroy()
 {
+  mDeviceContext = nsnull;
   return NS_OK;
 }
 
diff --git a/gfx/src/gtk/nsFontMetricsGTK.cpp b/gfx/src/gtk/nsFontMetricsGTK.cpp
index 9f0b5ef05b0a..85c1750d5b6e 100644
--- a/gfx/src/gtk/nsFontMetricsGTK.cpp
+++ b/gfx/src/gtk/nsFontMetricsGTK.cpp
@@ -1069,6 +1069,11 @@ nsFontMetricsGTK::~nsFontMetricsGTK()
 
   mWesternFont = nsnull;
 
+  if (mDeviceContext) {
+    mDeviceContext->FontMetricsDeleted(this);
+    mDeviceContext = nsnull;
+  }
+
   if (!--gFontMetricsGTKCount) {
     FreeGlobals();
   }
@@ -1237,7 +1242,7 @@ NS_IMETHODIMP nsFontMetricsGTK::Init(const nsFont& aFont, nsIAtom* aLangGroup,
 
 NS_IMETHODIMP  nsFontMetricsGTK::Destroy()
 {
-//  NS_IF_RELEASE(mDeviceContext);
+  mDeviceContext = nsnull;
   return NS_OK;
 }
 
diff --git a/gfx/src/mac/nsFontMetricsMac.cpp b/gfx/src/mac/nsFontMetricsMac.cpp
index 253260210ec2..9fef8f78dde6 100644
--- a/gfx/src/mac/nsFontMetricsMac.cpp
+++ b/gfx/src/mac/nsFontMetricsMac.cpp
@@ -63,6 +63,10 @@ nsFontMetricsMac :: ~nsFontMetricsMac()
     delete mFont;
     mFont = nsnull;
   }
+  if (mContext) {
+    mContext->FontMetricsDeleted(this);
+    mContext = nsnull;
+  }
 }
 
 //------------------------------------------------------------------------
@@ -240,6 +244,7 @@ void nsFontMetricsMac::RealizeFont()
 NS_IMETHODIMP
 nsFontMetricsMac::Destroy()
 {
+  mContext = nsnull;
   return NS_OK;
 }
 
diff --git a/gfx/src/nsDeviceContext.cpp b/gfx/src/nsDeviceContext.cpp
index 0ddf77e8be6c..62bf34f15c56 100644
--- a/gfx/src/nsDeviceContext.cpp
+++ b/gfx/src/nsDeviceContext.cpp
@@ -34,7 +34,7 @@
 #include "nsUnicharUtils.h"
 
 
-NS_IMPL_ISUPPORTS1(DeviceContextImpl, nsIDeviceContext)
+NS_IMPL_ISUPPORTS2(DeviceContextImpl, nsIDeviceContext, nsIObserver)
 
 DeviceContextImpl :: DeviceContextImpl()
 {
@@ -63,6 +63,10 @@ static PRBool PR_CALLBACK DeleteValue(nsHashKey* aKey, void* aValue, void* closu
 
 DeviceContextImpl :: ~DeviceContextImpl()
 {
+  nsCOMPtr<nsIObserverService> obs(do_GetService("@mozilla.org/observer-service;1"));
+  if (obs)
+    obs->RemoveObserver(this, "memory-pressure");
+
   if (nsnull != mFontCache)
   {
     delete mFontCache;
@@ -82,12 +86,27 @@ DeviceContextImpl :: ~DeviceContextImpl()
 
 }
 
+NS_IMETHODIMP
+DeviceContextImpl::Observe(nsISupports* aSubject, const char* aTopic, const PRUnichar* aSomeData)
+{
+  if (mFontCache && !nsCRT::strcmp(aTopic, "memory-pressure")) {
+    mFontCache->Compact();
+  }
+  return NS_OK;
+}
+
 NS_IMETHODIMP DeviceContextImpl :: Init(nsNativeWidget aWidget)
 {
   mWidget = aWidget;
 
   CommonInit();
 
+  // register as a memory-pressure observer to free font resources
+  // in low-memory situations.
+  nsCOMPtr<nsIObserverService> obs(do_GetService("@mozilla.org/observer-service;1"));
+  if (obs)
+    obs->AddObserver(this, "memory-pressure", PR_FALSE);
+
   return NS_OK;
 }
 
@@ -223,6 +242,14 @@ NS_IMETHODIMP DeviceContextImpl::CreateFontCache()
   return NS_OK;
 }
 
+NS_IMETHODIMP DeviceContextImpl::FontMetricsDeleted(const nsIFontMetrics* aFontMetrics)
+{
+  if (mFontCache) {
+    mFontCache->FontMetricsDeleted(aFontMetrics);
+  }
+  return NS_OK;
+}
+
 void
 DeviceContextImpl::GetLocaleLangGroup(void)
 {
@@ -604,24 +631,23 @@ nsFontCache :: GetMetricsFor(const nsFont& aFont, nsIAtom* aLangGroup,
   nsIFontMetrics *&aMetrics)
 {
   // First check our cache
-  PRInt32 n = mFontMetrics.Count()-1;
-
   // start from the end, which is where we put the most-recent-used element
-  for (PRInt32 cnt = n; cnt >= 0; --cnt)
-  {
-    nsIFontMetrics* metrics = NS_STATIC_CAST(nsIFontMetrics*, mFontMetrics[cnt]);
 
+  nsIFontMetrics* fm;
+  PRInt32 n = mFontMetrics.Count() - 1;
+  for (PRInt32 i = n; i >= 0; --i) {
+    fm = NS_STATIC_CAST(nsIFontMetrics*, mFontMetrics[i]);
     const nsFont* font;
-    metrics->GetFont(font);
-    if (aFont.Equals(*font)) {
+    fm->GetFont(font);
+    if (font->Equals(aFont)) {
       nsCOMPtr<nsIAtom> langGroup;
-      metrics->GetLangGroup(getter_AddRefs(langGroup));
+      fm->GetLangGroup(getter_AddRefs(langGroup));
       if (aLangGroup == langGroup.get()) {
-        if (cnt != n) {
+        if (i != n) {
           // promote it to the end of the cache
-          mFontMetrics.MoveElement(cnt, n);
+          mFontMetrics.MoveElement(i, n);
         }
-        NS_ADDREF(aMetrics = metrics);
+        NS_ADDREF(aMetrics = fm);
         return NS_OK;
       }
     }
@@ -629,28 +655,48 @@ nsFontCache :: GetMetricsFor(const nsFont& aFont, nsIAtom* aLangGroup,
 
   // It's not in the cache. Get font metrics and then cache them.
 
-  nsIFontMetrics *fm = nsnull;
+  aMetrics = nsnull;
   nsresult rv = CreateFontMetricsInstance(&fm);
-
-  if (NS_FAILED(rv)) {
-    aMetrics = nsnull;
-    return rv;
-  }
-
+  if (NS_FAILED(rv)) return rv;
   rv = fm->Init(aFont, aLangGroup, mContext);
+  if (NS_SUCCEEDED(rv)) {
+    // the mFontMetrics list has the "head" at the end, because append is
+    // cheaper than insert
+    mFontMetrics.AppendElement(fm);
+    aMetrics = fm;
+    NS_ADDREF(aMetrics);
+    return NS_OK;
+  }
+  fm->Destroy();
+  NS_RELEASE(fm);
 
-  if (NS_FAILED(rv)) {
-    aMetrics = nsnull;
-    return rv;
+  // One reason why Init() fails is because the system is running out of resources. 
+  // e.g., on Win95/98 only a very limited number of GDI objects are available.
+  // Compact the cache and try again.
+
+  Compact();
+  rv = CreateFontMetricsInstance(&fm);
+  if (NS_FAILED(rv)) return rv;
+  rv = fm->Init(aFont, aLangGroup, mContext);
+  if (NS_SUCCEEDED(rv)) {
+    mFontMetrics.AppendElement(fm);
+    aMetrics = fm;
+    NS_ADDREF(aMetrics);
+    return NS_OK;
+  }
+  fm->Destroy();
+  NS_RELEASE(fm);
+
+  // could not setup a new one, send an old one (XXX search a "best match"?)
+
+  n = mFontMetrics.Count() - 1; // could have changed in Compact()
+  if (n >= 0) {
+    aMetrics = NS_STATIC_CAST(nsIFontMetrics*, mFontMetrics[n]);
+    NS_ADDREF(aMetrics);
+    return NS_OK;
   }
 
-  // the mFontMetrics list has the "head" at the end, because append is
-  // cheaper than insert
-  mFontMetrics.AppendElement(fm);
-
-  NS_ADDREF(fm);
-  aMetrics = fm;
-  return NS_OK;
+  return rv;
 }
 
 /* PostScript and Xprint module may override this method to create 
@@ -663,14 +709,37 @@ nsFontCache::CreateFontMetricsInstance(nsIFontMetrics** fm)
   return CallCreateInstance(kFontMetricsCID, fm);
 }
 
+nsresult nsFontCache::FontMetricsDeleted(const nsIFontMetrics* aFontMetrics)
+{
+  mFontMetrics.RemoveElement((void*)aFontMetrics);
+  return NS_OK;
+}
+
+nsresult nsFontCache::Compact()
+{
+  // Need to loop backward because the running element can be removed on the way
+  for (PRInt32 i = mFontMetrics.Count()-1; i >= 0; --i) {
+    nsIFontMetrics* fm = NS_STATIC_CAST(nsIFontMetrics*, mFontMetrics[i]);
+    nsIFontMetrics* oldfm = fm;
+    // Destroy() isn't here because we want our device context to be notified
+    NS_RELEASE(fm); // this will reset fm to nsnull
+    // if the font is really gone, it would have called back in
+    // FontMetricsDeleted() and would have removed itself
+    if (mFontMetrics.IndexOf(oldfm) >= 0) {
+      // nope, the font is still there, so let's hold onto it too
+      NS_ADDREF(oldfm);
+    }
+  }
+  return NS_OK;
+}
 
 nsresult nsFontCache :: Flush()
 {
-  PRInt32 i, n = mFontMetrics.Count();
-
-  for (i = 0; i < n; i++)
-  {
-    nsIFontMetrics* fm = (nsIFontMetrics*) mFontMetrics.ElementAt(i);
+  for (PRInt32 i = mFontMetrics.Count()-1; i >= 0; --i) {
+    nsIFontMetrics* fm = NS_STATIC_CAST(nsIFontMetrics*, mFontMetrics[i]);
+    // Destroy() will unhook our device context from the fm so that we won't
+    // waste time in triggering the notification of FontMetricsDeleted()
+    // in the subsequent release
     fm->Destroy();
     NS_RELEASE(fm);
   }
diff --git a/gfx/src/os2/nsFontMetricsOS2.cpp b/gfx/src/os2/nsFontMetricsOS2.cpp
index c9426ccdd6e8..ca03446ddd57 100644
--- a/gfx/src/os2/nsFontMetricsOS2.cpp
+++ b/gfx/src/os2/nsFontMetricsOS2.cpp
@@ -274,10 +274,12 @@ nsFontMetricsOS2::nsFontMetricsOS2()
 
 nsFontMetricsOS2::~nsFontMetricsOS2()
 {
-   Destroy();
-
    delete mFont;
    delete mFontHandle;
+  if (mDeviceContext) {
+    mDeviceContext->FontMetricsDeleted(this);
+    mDeviceContext = nsnull;
+  }
   if (0 == --gFontMetricsOS2Count) {
     FreeGlobals();
   }
@@ -321,6 +323,7 @@ nsFontMetricsOS2::Init( const nsFont &aFont,  nsIAtom* aLangGroup,
 
 nsresult nsFontMetricsOS2::Destroy()
 {
+   mDeviceContext = nsnull;
    return NS_OK;
 }
 
diff --git a/gfx/src/photon/nsFontMetricsPh.cpp b/gfx/src/photon/nsFontMetricsPh.cpp
index e2b7cdec7063..d3fdd26f77ab 100644
--- a/gfx/src/photon/nsFontMetricsPh.cpp
+++ b/gfx/src/photon/nsFontMetricsPh.cpp
@@ -125,9 +125,12 @@ nsFontMetricsPh :: ~nsFontMetricsPh( )
 		  delete mFont;
 		  mFont = nsnull;
 	  }
-	mDeviceContext = nsnull;
 	if (mFontHandle)
 	   free (mFontHandle);
+  if (mDeviceContext) {
+    mDeviceContext->FontMetricsDeleted(this);
+    mDeviceContext = nsnull;
+  }
 	FreeGlobals();
 }
 
diff --git a/gfx/src/ps/nsFontMetricsPS.cpp b/gfx/src/ps/nsFontMetricsPS.cpp
index 90d46a3f0725..255e620ef5f2 100644
--- a/gfx/src/ps/nsFontMetricsPS.cpp
+++ b/gfx/src/ps/nsFontMetricsPS.cpp
@@ -66,8 +66,10 @@ nsFontMetricsPS :: ~nsFontMetricsPS()
     mAFMInfo = nsnull;
   }
 
-
-  mDeviceContext = nsnull;
+  if (mDeviceContext) {
+    mDeviceContext->FontMetricsDeleted(this);
+    mDeviceContext = nsnull;
+  }
 }
 
 NS_IMPL_ISUPPORTS1(nsFontMetricsPS, nsIFontMetrics)
diff --git a/gfx/src/qt/nsFontMetricsQT.cpp b/gfx/src/qt/nsFontMetricsQT.cpp
index 486e265de5d6..507247b97656 100644
--- a/gfx/src/qt/nsFontMetricsQT.cpp
+++ b/gfx/src/qt/nsFontMetricsQT.cpp
@@ -684,6 +684,10 @@ nsFontMetricsQT::~nsFontMetricsQT()
     delete mUserDefinedFont;
     mUserDefinedFont = nsnull;
   } 
+  if (mDeviceContext) {
+    mDeviceContext->FontMetricsDeleted(this);
+    mDeviceContext = nsnull;
+  }
   if (!--gFontMetricsQTCount) {
     FreeGlobals();
     if (mQFontDB) {
@@ -893,6 +897,7 @@ QFontDatabase *nsFontMetricsQT::GetQFontDB()
  
 NS_IMETHODIMP nsFontMetricsQT::Destroy()
 {
+  mDeviceContext = nsnull;
   return NS_OK;
 }
 
diff --git a/gfx/src/windows/nsFontMetricsWin.cpp b/gfx/src/windows/nsFontMetricsWin.cpp
index ea421bc16a0f..e36992e4e35d 100644
--- a/gfx/src/windows/nsFontMetricsWin.cpp
+++ b/gfx/src/windows/nsFontMetricsWin.cpp
@@ -403,7 +403,10 @@ nsFontMetricsWin::~nsFontMetricsWin()
   }
   mLoadedFonts.Clear();
 
-  mDeviceContext = nsnull;
+  if (mDeviceContext) {
+    mDeviceContext->FontMetricsDeleted(this);
+    mDeviceContext = nsnull;
+  }
 }
 
 #ifdef LEAK_DEBUG
diff --git a/gfx/src/xlib/nsFontMetricsXlib.cpp b/gfx/src/xlib/nsFontMetricsXlib.cpp
index 99d88ff225af..985e9af0b8f9 100644
--- a/gfx/src/xlib/nsFontMetricsXlib.cpp
+++ b/gfx/src/xlib/nsFontMetricsXlib.cpp
@@ -985,6 +985,11 @@ nsFontMetricsXlib::~nsFontMetricsXlib()
   mWesternFont = nsnull;
   mFontHandle = nsnull;
 
+  if (mDeviceContext) {
+    mDeviceContext->FontMetricsDeleted(this);
+    mDeviceContext = nsnull;
+  }
+
   if (!--gFontMetricsXlibCount) {
     FreeGlobals();
   }
@@ -1192,7 +1197,7 @@ nsFontMetricsXlib::Init(const nsFont& aFont, nsIAtom* aLangGroup,
 
 NS_IMETHODIMP  nsFontMetricsXlib::Destroy()
 {
-//  NS_IF_RELEASE(mDeviceContext);
+  mDeviceContext = nsnull;
   return NS_OK;
 }