Index: doc/FileSystem.3
==================================================================
--- doc/FileSystem.3
+++ doc/FileSystem.3
@@ -412,11 +412,11 @@
 .PP
 \fBTcl_FSEvalFileEx\fR reads the file given by \fIpathPtr\fR using
 the encoding identified by \fIencodingName\fR and evaluates
 its contents as a Tcl script. It returns the same information as
 \fBTcl_EvalObjEx\fR.
-If \fIencodingName\fR is NULL, the system encoding is used for
+If \fIencodingName\fR is NULL, the utf-8 encoding is used for
 reading the file contents.
 If the file could not be read then a Tcl error is returned to describe
 why the file could not be read.
 The eofchar for files is
 .QW \e32
@@ -428,11 +428,11 @@
 or
 .QW \eu001a ,
 which will be safely substituted by the Tcl interpreter into
 .QW ^Z .
 \fBTcl_FSEvalFile\fR is a simpler version of
-\fBTcl_FSEvalFileEx\fR that always uses the system encoding
+\fBTcl_FSEvalFileEx\fR that always uses the utf-8 encoding
 when reading the file.
 .PP
 \fBTcl_FSLoadFile\fR dynamically loads a binary code file into memory and
 returns the addresses of two procedures within that file, if they are
 defined. The appropriate function for the filesystem to which \fIpathPtr\fR

Index: doc/source.n
==================================================================
--- doc/source.n
+++ doc/source.n
@@ -45,11 +45,11 @@
 .PP
 A leading BOM (Byte order mark) contained in the file is ignored for unicode encodings (utf-8, utf-16, ucs-2).
 .PP
 The \fB\-encoding\fR option is used to specify the encoding of
 the data stored in \fIfileName\fR.  When the \fB\-encoding\fR option
-is omitted, the system encoding is assumed.
+is omitted, the utf-8 encoding is assumed.
 .SH EXAMPLE
 .PP
 Run the script in the file \fBfoo.tcl\fR and then the script in the
 file \fBbar.tcl\fR:
 .PP

Index: generic/tclIOUtil.c
==================================================================
--- generic/tclIOUtil.c
+++ generic/tclIOUtil.c
@@ -1682,11 +1682,11 @@
     Tcl_Interp *interp,		/* Interpreter that evaluates the script. */
     Tcl_Obj *pathPtr,		/* Pathname of the file to process.
 				 * Tilde-substitution is performed on this
 				 * pathname. */
     const char *encodingName)	/* Either the name of an encoding or NULL to
-				   use the system encoding. */
+				   use the utf-8 encoding. */
 {
     int length, result = TCL_ERROR;
     Tcl_StatBuf statBuf;
     Tcl_Obj *oldScriptFile;
     Interp *iPtr;
@@ -1720,20 +1720,20 @@
 
     Tcl_SetChannelOption(interp, chan, "-eofchar", "\32 {}");
 
     /*
      * If the encoding is specified, set the channel to that encoding.
-     * Otherwise don't touch it, leaving things up to the system encoding.  If
-     * the encoding is unknown report an error.
+     * Otherwise use utf-8.  If the encoding is unknown report an error.
      */
 
-    if (encodingName != NULL) {
-	if (Tcl_SetChannelOption(interp, chan, "-encoding", encodingName)
-		!= TCL_OK) {
-	    Tcl_Close(interp,chan);
-	    return result;
-	}
+    if (encodingName == NULL) {
+	encodingName = "utf-8";
+    }
+    if (Tcl_SetChannelOption(interp, chan, "-encoding", encodingName)
+	    != TCL_OK) {
+	Tcl_Close(interp,chan);
+	return result;
     }
 
     TclNewObj(objPtr);
     Tcl_IncrRefCount(objPtr);
 
@@ -1819,11 +1819,11 @@
     Tcl_Interp *interp,		/* Interpreter in which to evaluate the script. */
     Tcl_Obj *pathPtr,		/* Pathname of a file containing the script to
 				 * evaluate. Tilde-substitution is performed on
 				 * this pathname. */
     const char *encodingName)	/* The name of an encoding to use, or NULL to
-				 *  use the system encoding. */
+				 *  use the utf-8 encoding. */
 {
     Tcl_StatBuf statBuf;
     Tcl_Obj *oldScriptFile, *objPtr;
     Interp *iPtr;
     Tcl_Channel chan;
@@ -1856,20 +1856,20 @@
 
     Tcl_SetChannelOption(interp, chan, "-eofchar", "\32 {}");
 
     /*
      * If the encoding is specified, set the channel to that encoding.
-     * Otherwise don't touch it, leaving things up to the system encoding.  If
-     * the encoding is unknown report an error.
+     * Otherwise use utf-8.  If the encoding is unknown report an error.
      */
 
-    if (encodingName != NULL) {
-	if (Tcl_SetChannelOption(interp, chan, "-encoding", encodingName)
-		!= TCL_OK) {
-	    Tcl_Close(interp,chan);
-	    return TCL_ERROR;
-	}
+    if (encodingName == NULL) {
+	encodingName = "utf-8";
+    }
+    if (Tcl_SetChannelOption(interp, chan, "-encoding", encodingName)
+	    != TCL_OK) {
+	Tcl_Close(interp, chan);
+	return TCL_ERROR;
     }
 
     TclNewObj(objPtr);
     Tcl_IncrRefCount(objPtr);
 

Index: generic/tclZlib.c
==================================================================
--- generic/tclZlib.c
+++ generic/tclZlib.c
@@ -3943,11 +3943,11 @@
      */
 
     cfg[0].key = "zlibVersion";
     cfg[0].value = zlibVersion();
     cfg[1].key = NULL;
-    Tcl_RegisterConfig(interp, "zlib", cfg, "iso8859-1");
+    Tcl_RegisterConfig(interp, "zlib", cfg, "utf-8");
 
     /*
      * Allow command type introspection to do something sensible with streams.
      */
 

Index: library/clock.tcl
==================================================================
--- library/clock.tcl
+++ library/clock.tcl
@@ -3312,11 +3312,11 @@
 	return -code error \
 	    -errorcode [list CLOCK badTimeZone $:fileName] \
 	    "time zone \":$fileName\" not valid"
     }
     try {
-	source -encoding utf-8 [file join $DataDir $fileName]
+	source [file join $DataDir $fileName]
     } on error {} {
 	return -code error \
 	    -errorcode [list CLOCK badTimeZone :$fileName] \
 	    "time zone \":$fileName\" not found"
     }

Index: library/init.tcl
==================================================================
--- library/init.tcl
+++ library/init.tcl
@@ -110,11 +110,11 @@
 	# Auto-loading stubs for 'clock.tcl'
 
 	foreach cmd {add format scan} {
 	    proc ::tcl::clock::$cmd args {
 		variable TclLibDir
-		source -encoding utf-8 [file join $TclLibDir clock.tcl]
+		source [file join $TclLibDir clock.tcl]
 		return [uplevel 1 [info level 0]]
 	    }
 	}
 
 	rename ::tcl::initClock {}

Index: library/safe.tcl
==================================================================
--- library/safe.tcl
+++ library/safe.tcl
@@ -935,11 +935,11 @@
 	    Log $child "attempt to use the identity encoding"
 	    return -code error "permission denied"
 	}
     } else {
 	set at 0
-	set encoding {}
+	set encoding utf-8
     }
     if {$argc != 1} {
 	set msg "wrong # args: should be \"source ?-encoding E? fileName\""
 	Log $child "$msg ($args)"
 	return -code error $msg
@@ -978,14 +978,11 @@
     # doesn't leak so much. [Bug 2913625]
     set old [::interp eval $child {info script}]
     set replacementMsg "script error"
     set code [catch {
 	set f [open $realfile]
-	fconfigure $f -eofchar \032
-	if {$encoding ne ""} {
-	    fconfigure $f -encoding $encoding
-	}
+	fconfigure $f -encoding $encoding -eofchar \032
 	set contents [read $f]
 	close $f
 	::interp eval $child [list info script $file]
     } msg opt]
     if {$code == 0} {

Index: library/tm.tcl
==================================================================
--- library/tm.tcl
+++ library/tm.tcl
@@ -265,11 +265,11 @@
 		    #
 		    # Right now LOCATE's implementation assumes that the path
 		    # of the package file is the last element in the list.
 
 		    package ifneeded $pkgname $pkgversion \
-			"[::list package provide $pkgname $pkgversion];[::list source -encoding utf-8 $file]"
+			"[::list package provide $pkgname $pkgversion];[::list source $file]"
 
 		    # We abort in this unknown handler only if we got a
 		    # satisfying candidate for the requested package.
 		    # Otherwise we still have to fallback to the regular
 		    # package search to complete the processing.

Index: unix/README
==================================================================
--- unix/README
+++ unix/README
@@ -89,11 +89,11 @@
 	--enable-dtrace		Enable tcl DTrace provider (if DTrace is
 				available on the platform), c.f. tclDTrace.d
 				for descriptions of the probes made available,
 				see http://wiki.tcl.tk/DTrace for more details
 	--with-encoding=ENCODING Specifies the encoding for compile-time
-				configuration values. Defaults to iso8859-1,
+				configuration values. Defaults to utf-8,
 				which is also sufficient for ASCII.
 	--with-tzdata=FLAG	Specifies whether to install timezone data. By
 				default, the configure script tries to detect
 				whether a usable timezone database is present
 				on the system already.

Index: unix/configure
==================================================================
--- unix/configure
+++ unix/configure
@@ -1428,11 +1428,11 @@
 
 Optional Packages:
   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
   --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
   --with-encoding         encoding for configuration values (default:
-                          iso8859-1)
+                          utf-8)
   --with-system-libtommath
                           use external libtommath (default: true if available,
                           false otherwise)
   --with-tzdata           install timezone data (default: autodetect)
 
@@ -3980,11 +3980,11 @@
 #define TCL_CFGVAL_ENCODING "${with_tcencoding}"
 _ACEOF
 
     else
 
-$as_echo "#define TCL_CFGVAL_ENCODING \"iso8859-1\"" >>confdefs.h
+$as_echo "#define TCL_CFGVAL_ENCODING \"utf-8\"" >>confdefs.h
 
     fi
 
 
 #--------------------------------------------------------------------

Index: unix/tcl.m4
==================================================================
--- unix/tcl.m4
+++ unix/tcl.m4
@@ -2443,18 +2443,18 @@
 #--------------------------------------------------------------------
 
 AC_DEFUN([SC_TCL_CFG_ENCODING], [
     AC_ARG_WITH(encoding,
 	AC_HELP_STRING([--with-encoding],
-	    [encoding for configuration values (default: iso8859-1)]),
+	    [encoding for configuration values (default: utf-8)]),
 	with_tcencoding=${withval})
 
     if test x"${with_tcencoding}" != x ; then
 	AC_DEFINE_UNQUOTED(TCL_CFGVAL_ENCODING,"${with_tcencoding}",
 	    [What encoding should be used for embedded configuration info?])
     else
-	AC_DEFINE(TCL_CFGVAL_ENCODING,"iso8859-1",
+	AC_DEFINE(TCL_CFGVAL_ENCODING,"utf-8",
 	    [What encoding should be used for embedded configuration info?])
     fi
 ])
 
 #--------------------------------------------------------------------

Index: win/configure
==================================================================
--- win/configure
+++ win/configure
@@ -3747,12 +3747,11 @@
 	cat >>confdefs.h <<_ACEOF
 #define TCL_CFGVAL_ENCODING "${with_tcencoding}"
 _ACEOF
 
     else
-	# Default encoding on windows is not "iso8859-1"
-	$as_echo "#define TCL_CFGVAL_ENCODING \"cp1252\"" >>confdefs.h
+	$as_echo "#define TCL_CFGVAL_ENCODING \"utf-8\"" >>confdefs.h
 
     fi
 
 
 #--------------------------------------------------------------------

Index: win/makefile.vc
==================================================================
--- win/makefile.vc
+++ win/makefile.vc
@@ -114,11 +114,11 @@
 #	TESTPAT=<file>
 #		Reads the tests requested to be run from this file.
 #
 #	CFG_ENCODING=encoding
 #		name of encoding for configuration information. Defaults
-#		to cp1252
+#		to utf-8
 #
 # Examples:
 #       c:\tcl_src\win\>nmake -f makefile.vc release
 #       c:\tcl_src\win\>nmake -f makefile.vc test
 #       c:\tcl_src\win\>nmake -f makefile.vc install INSTALLDIR=c:\progra~1\tcl

Index: win/rules.vc
==================================================================
--- win/rules.vc
+++ win/rules.vc
@@ -502,11 +502,11 @@
 _VC_MANIFEST_EMBED_EXE=if exist $@.manifest mt -nologo -manifest $@.manifest -outputresource:$@;1
 _VC_MANIFEST_EMBED_DLL=if exist $@.manifest mt -nologo -manifest $@.manifest -outputresource:$@;2
 !endif
 
 !ifndef CFG_ENCODING
-CFG_ENCODING	= \"cp1252\"
+CFG_ENCODING	= \"utf-8\"
 !endif
 
 ################################################################
 # 4. Build the nmakehlp program
 # This is a helper app we need to overcome nmake's limiting

Index: win/tcl.m4
==================================================================
--- win/tcl.m4
+++ win/tcl.m4
@@ -1083,12 +1083,11 @@
     AC_ARG_WITH(encoding, [  --with-encoding         encoding for configuration values], with_tcencoding=${withval})
 
     if test x"${with_tcencoding}" != x ; then
 	AC_DEFINE_UNQUOTED(TCL_CFGVAL_ENCODING,"${with_tcencoding}")
     else
-	# Default encoding on windows is not "iso8859-1"
-	AC_DEFINE(TCL_CFGVAL_ENCODING,"cp1252")
+	AC_DEFINE(TCL_CFGVAL_ENCODING,"utf-8")
     fi
 ])
 
 #--------------------------------------------------------------------
 # SC_EMBED_MANIFEST