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diff --git a/INSTALL b/INSTALL
index 470acfc..bc21709 100644
--- a/INSTALL
+++ b/INSTALL
@@ -20,7 +20,7 @@ The basic steps to build and install perl5 on a Unix system are:
 Each of these is explained in further detail below.
 
 For information on non-Unix systems, see the section on
-L<"Porting Information"> below.
+L<"Porting information"> below.
 
 =head1 DESCRIPTION
 
@@ -616,11 +616,22 @@ In a future version of perl, these might be enabled by default.
 
 =over 4
 
+=item -DDEBUGGING_MSTATS
+
+If C<DEBUGGING_MSTATS> is defined, you can extract malloc
+statistics from the Perl interpreter.  The overhead this imposes is not
+large (perl just twiddles integers at malloc/free/sbrk time).  When you
+run perl with the environment variable C<PERL_DEBUG_MSTATS> set to
+either 1 or 2, the interpreter will dump statistics to stderr at exit
+time and (with a value of 2) after compilation.  If you install the
+Devel::Peek module you can get the statistics whenever you like by
+invoking its mstat() function.
+
 =item -DEMERGENCY_SBRK
 
-If this macro is defined, running out of memory need not be a fatal
-error: a memory pool can allocated by assigning to the special
-variable C<$^M>.
+If C<EMERGENCY_SBRK> is defined, running out of memory need not be a
+fatal error: a memory pool can allocated by assigning to the special
+variable C<$^M>.  See L<perlvar> for more details.
 
 =item -DPACK_MALLOC
 
@@ -648,6 +659,23 @@ negligible.
 
 =back
 
+=head2 Building a debugging perl
+
+You can run perl scripts under the perl debugger at any time with
+B<perl -d>.  If, however, you want to debug perl itself,
+you probably want to do
+
+	sh Configure -Doptimize='-g'
+
+This will do two things:  First, it will force compilation to use
+B<cc -g> so that you can use your system's debugger on the executable.
+Second, it will add a C<-DDEBUGGING> to your ccflags variable in
+F<config.sh> so that you can use B<perl -D> to access perl's internal
+state.
+
+If you are using a shared libperl, see the warnings about multiple
+versions of perl under L<Building a shared libperl.so Perl library>.
+
 =head2 Other Compiler Flags
 
 For most users, all of the Configure defaults are fine.  However,
@@ -787,7 +815,7 @@ mechanism.
 
 =item Porting information
 
-Specific information for the OS/2, Plan9, VMS and Win32 ports are in the
+Specific information for the OS/2, Plan9, VMS and Win32 ports is in the
 corresponding subdirectories.  Additional information, including
 a glossary of all those config.sh variables, is in the Porting
 subdirectory.
@@ -1274,4 +1302,4 @@ from the original README by Larry Wall.
 
 =head1 LAST MODIFIED
 
-$Id: INSTALL,v 1.3 1997/02/28 16:34:11 doughera Released $
+$Id: INSTALL,v 1.8 1997/03/21 16:21:53 doughera Released $