diff --git a/tools/tools/README b/tools/tools/README
index 2a7fca1a3aae..b305823f6169 100644
--- a/tools/tools/README
+++ b/tools/tools/README
@@ -1,4 +1,4 @@
-#	$Id: README,v 1.13 1998/12/15 16:51:48 cracauer Exp $
+#	$Id: README,v 1.14 1998/12/17 12:21:19 cracauer Exp $
 
 This directory is for tools.
 
@@ -22,3 +22,6 @@ tcl_bmake	Generates a bmake Makefile for src/lib/libtcl.
 upgrade         Scripts used for upgrading an installed system.
 vop_table	Generates a HTML document that shows all the VOP's in
 		the kernel.
+diffburst	Reads the output of 'diff -r' and splits it into separate
+		patch files, one per file. The files are named 'patch-XX'
+		where XX is aa, ab, ac, ... Useful when creating ports.
diff --git a/tools/tools/diffburst/Makefile b/tools/tools/diffburst/Makefile
new file mode 100644
index 000000000000..4e58e4cdd866
--- /dev/null
+++ b/tools/tools/diffburst/Makefile
@@ -0,0 +1,9 @@
+# $Id: Makefile,v 1.1 1997/12/06 00:44:04 archie Exp $
+
+PROG=		diffburst
+SRCS=		main.c
+MAN1=		diffburst.1
+
+COPTS+=		-g -Wall
+
+.include <bsd.prog.mk>
diff --git a/tools/tools/diffburst/diffburst.1 b/tools/tools/diffburst/diffburst.1
new file mode 100644
index 000000000000..91a33091ab52
--- /dev/null
+++ b/tools/tools/diffburst/diffburst.1
@@ -0,0 +1,19 @@
+.Dd Jan 7, 1999
+.Dt DIFFBURST 1
+.Os BSD 4.4
+.Sh NAME
+.Nm diffburst
+.Nd split recursive diff output into separate files
+.Sh SYNOPSIS
+.Nm diffburst < input
+.Sh DESCRIPTION
+.Nm
+reads the output of a recursive diff from standard input,
+and writes it back out as a series of patchfiles, where each patchfile
+contains the diff for a single file. The files are named
+patch-aa, patch-ab, and so on.
+.Pp
+This program is intended to aid in developing FreeBSD ports,
+where the 'one patchfile per file' rule applies.
+.Sh AUTHOR
+Archie Cobbs <archie@whistle.com>
diff --git a/tools/tools/diffburst/main.c b/tools/tools/diffburst/main.c
new file mode 100644
index 000000000000..a38e40c5e1f1
--- /dev/null
+++ b/tools/tools/diffburst/main.c
@@ -0,0 +1,44 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <err.h>
+
+/* Split a recursive diff into sub-patches to satisfy the requirement
+  that each patch only patch a single file */
+
+int
+main(int ac, char *av[])
+{
+  int	ln;
+  char	line[8192];
+  char	suf[2] = { 'a', 'a' };
+  FILE	*fp = NULL;
+
+  memset(line, 0, sizeof(line));
+  for (ln = 1; fgets(line, sizeof(line) - 1, stdin); ln++)
+  {
+    if (line[strlen(line) - 1] != '\n')
+      errx(1, "line %d is too long", ln);
+    if (!strncmp(line, "diff", 4) && fp != NULL)
+    {
+      fclose(fp);
+      fp = NULL;
+    }
+    if (fp == NULL)
+    {
+      char	name[200];
+
+      snprintf(name, sizeof(name), "patch-%c%c", suf[0], suf[1]);
+      if (suf[1]++ == 'z')
+      {
+	suf[1] = 'a';
+	suf[0]++;
+      }
+      if ((fp = fopen(name, "w")) == NULL)
+	err(1, "%s", name);
+    }
+    fprintf(fp, "%s", line);
+  }
+  return(0);
+}
+