diff --git a/src/cmd/gobuild/makefile.go b/src/cmd/gobuild/makefile.go
index 229dbe21941..e5eb47f19ee 100644
--- a/src/cmd/gobuild/makefile.go
+++ b/src/cmd/gobuild/makefile.go
@@ -96,7 +96,7 @@ var makefileTemplate =
 	"	cp {ObjDir}$D/{Name}.a $(GOROOT)/pkg$D/{Name}.a\n"
 	"{.end}\n"
 
-func argsFmt(w io.Write, x interface{}, format string) {
+func argsFmt(w io.Writer, x interface{}, format string) {
 	args := x.([]string);
 	fmt.Fprint(w, "#");
 	for i, a := range args {
@@ -104,17 +104,17 @@ func argsFmt(w io.Write, x interface{}, format string) {
 	}
 }
 
-func basenameFmt(w io.Write, x interface{}, format string) {
+func basenameFmt(w io.Writer, x interface{}, format string) {
 	t := fmt.Sprint(x);
 	t = t[0:len(t)-len(path.Ext(t))];
 	fmt.Fprint(w, MakeString(t));
 }
 
-func plus1Fmt(w io.Write, x interface{}, format string) {
+func plus1Fmt(w io.Writer, x interface{}, format string) {
 	fmt.Fprint(w, x.(int) + 1);
 }
 
-func makeFmt(w io.Write, x interface{}, format string) {
+func makeFmt(w io.Writer, x interface{}, format string) {
 	fmt.Fprint(w, MakeString(fmt.Sprint(x)));
 }
 
diff --git a/src/lib/bufio/bufio.go b/src/lib/bufio/bufio.go
index 23f55999382..c3d1fc715ab 100644
--- a/src/lib/bufio/bufio.go
+++ b/src/lib/bufio/bufio.go
@@ -47,17 +47,17 @@ func copySlice(dst []byte, src []byte) {
 // BufRead implements buffering for an io.Read object.
 type BufRead struct {
 	buf []byte;
-	rd io.Read;
+	rd io.Reader;
 	r, w int;
 	err os.Error;
 	lastbyte int;
 }
 
 // NewBufReadSize creates a new BufRead whose buffer has the specified size,
-// which must be greater than zero.  If the argument io.Read is already a
+// which must be greater than zero.  If the argument io.Reader is already a
 // BufRead with large enough size, it returns the underlying BufRead.
 // It returns the BufRead and any error.
-func NewBufReadSize(rd io.Read, size int) (*BufRead, os.Error) {
+func NewBufReadSize(rd io.Reader, size int) (*BufRead, os.Error) {
 	if size <= 0 {
 		return nil, BadBufSize
 	}
@@ -74,7 +74,7 @@ func NewBufReadSize(rd io.Read, size int) (*BufRead, os.Error) {
 }
 
 // NewBufRead returns a new BufRead whose buffer has the default size.
-func NewBufRead(rd io.Read) *BufRead {
+func NewBufRead(rd io.Reader) *BufRead {
 	b, err := NewBufReadSize(rd, defaultBufSize);
 	if err != nil {
 		// cannot happen - defaultBufSize is a valid size
@@ -378,19 +378,19 @@ func (b *BufRead) ReadLineString(delim byte, savedelim bool) (line string, err o
 
 // buffered output
 
-// BufWrite implements buffering for an io.Write object.
+// BufWrite implements buffering for an io.Writer object.
 type BufWrite struct {
 	err os.Error;
 	buf []byte;
 	n int;
-	wr io.Write;
+	wr io.Writer;
 }
 
 // NewBufWriteSize creates a new BufWrite whose buffer has the specified size,
-// which must be greater than zero. If the argument io.Write is already a
+// which must be greater than zero. If the argument io.Writer is already a
 // BufWrite with large enough size, it returns the underlying BufWrite.
 // It returns the BufWrite and any error.
-func NewBufWriteSize(wr io.Write, size int) (*BufWrite, os.Error) {
+func NewBufWriteSize(wr io.Writer, size int) (*BufWrite, os.Error) {
 	if size <= 0 {
 		return nil, BadBufSize
 	}
@@ -406,7 +406,7 @@ func NewBufWriteSize(wr io.Write, size int) (*BufWrite, os.Error) {
 }
 
 // NewBufWrite returns a new BufWrite whose buffer has the default size.
-func NewBufWrite(wr io.Write) *BufWrite {
+func NewBufWrite(wr io.Writer) *BufWrite {
 	b, err := NewBufWriteSize(wr, defaultBufSize);
 	if err != nil {
 		// cannot happen - defaultBufSize is valid size
@@ -415,7 +415,7 @@ func NewBufWrite(wr io.Write) *BufWrite {
 	return b;
 }
 
-// Flush writes any buffered data to the underlying io.Write.
+// Flush writes any buffered data to the underlying io.Writer.
 func (b *BufWrite) Flush() os.Error {
 	if b.err != nil {
 		return b.err
@@ -505,7 +505,7 @@ func (b *BufWrite) WriteByte(c byte) os.Error {
 // buffered input and output
 
 // BufReadWrite stores (a pointer to) a BufRead and a BufWrite.
-// It implements io.ReadWrite.
+// It implements io.ReadWriter.
 type BufReadWrite struct {
 	*BufRead;
 	*BufWrite;
diff --git a/src/lib/bufio/bufio_test.go b/src/lib/bufio/bufio_test.go
index 00ab4a41429..4b00cae3ae3 100644
--- a/src/lib/bufio/bufio_test.go
+++ b/src/lib/bufio/bufio_test.go
@@ -24,7 +24,7 @@ type byteReader struct {
 	p []byte
 }
 
-func newByteReader(p []byte) io.Read {
+func newByteReader(p []byte) io.Reader {
 	b := new(byteReader);
 	b.p = p;
 	return b
@@ -46,7 +46,7 @@ type halfByteReader struct {
 	p []byte
 }
 
-func newHalfByteReader(p []byte) io.Read {
+func newHalfByteReader(p []byte) io.Reader {
 	b := new(halfByteReader);
 	b.p = p;
 	return b
@@ -67,10 +67,10 @@ func (b *halfByteReader) Read(p []byte) (int, os.Error) {
 
 // Reads from a reader and rot13s the result.
 type rot13Reader struct {
-	r io.Read
+	r io.Reader
 }
 
-func newRot13Reader(r io.Read) *rot13Reader {
+func newRot13Reader(r io.Reader) *rot13Reader {
 	r13 := new(rot13Reader);
 	r13.r = r;
 	return r13
@@ -95,11 +95,11 @@ func (r13 *rot13Reader) Read(p []byte) (int, os.Error) {
 
 type readMaker struct {
 	name string;
-	fn func([]byte) io.Read;
+	fn func([]byte) io.Reader;
 }
 var readMakers = []readMaker {
-	readMaker{ "full", func(p []byte) io.Read { return newByteReader(p) } },
-	readMaker{ "half", func(p []byte) io.Read { return newHalfByteReader(p) } },
+	readMaker{ "full", func(p []byte) io.Reader { return newByteReader(p) } },
+	readMaker{ "half", func(p []byte) io.Reader { return newHalfByteReader(p) } },
 }
 
 // Call ReadLineString (which ends up calling everything else)
diff --git a/src/lib/fmt/print.go b/src/lib/fmt/print.go
index d52dcfc10af..229c264757a 100644
--- a/src/lib/fmt/print.go
+++ b/src/lib/fmt/print.go
@@ -27,7 +27,7 @@ import (
 )
 
 // Formatter represents the printer state passed to custom formatters.
-// It provides access to the io.Write interface plus information about
+// It provides access to the io.Writer interface plus information about
 // the flags and options for the operand's format specifier.
 type Formatter interface {
 	// Write is the function to call to emit formatted output to be printed.
@@ -52,7 +52,7 @@ type Format interface {
 // returns a string, which defines the ``native'' format for that object.
 // Any such object will be printed using that method if passed
 // as operand to a %s or %v format or to an unformatted printer such as Print.
-type String interface {
+type Stringer interface {
 	String() string
 }
 
@@ -149,7 +149,7 @@ func (p *pp) doprint(v reflect.StructValue, addspace, addnewline bool);
 // These routines end in 'f' and take a format string.
 
 // Fprintf formats according to a format specifier and writes to w.
-func Fprintf(w io.Write, format string, a ...) (n int, error os.Error) {
+func Fprintf(w io.Writer, format string, a ...) (n int, error os.Error) {
 	v := reflect.NewValue(a).(reflect.StructValue);
 	p := newPrinter();
 	p.doprintf(format, v);
@@ -176,7 +176,7 @@ func Sprintf(format string, a ...) string {
 
 // Fprint formats using the default formats for its operands and writes to w.
 // Spaces are added between operands when neither is a string.
-func Fprint(w io.Write, a ...) (n int, error os.Error) {
+func Fprint(w io.Writer, a ...) (n int, error os.Error) {
 	v := reflect.NewValue(a).(reflect.StructValue);
 	p := newPrinter();
 	p.doprint(v, false, false);
@@ -207,7 +207,7 @@ func Sprint(a ...) string {
 
 // Fprintln formats using the default formats for its operands and writes to w.
 // Spaces are always added between operands and a newline is appended.
-func Fprintln(w io.Write, a ...) (n int, error os.Error) {
+func Fprintln(w io.Writer, a ...) (n int, error os.Error) {
 	v := reflect.NewValue(a).(reflect.StructValue);
 	p := newPrinter();
 	p.doprint(v, true, true);
@@ -364,7 +364,7 @@ func parsenum(s string, start, end int) (n int, got bool, newi int) {
 func (p *pp) printField(field reflect.Value) (was_string bool) {
 	inter := field.Interface();
 	if inter != nil {
-		if stringer, ok := inter.(String); ok {
+		if stringer, ok := inter.(Stringer); ok {
 			p.addstr(stringer.String());
 			return false;	// this value is not a string
 		}
@@ -628,7 +628,7 @@ func (p *pp) doprintf(format string, v reflect.StructValue) {
 			case 's':
 				if inter != nil {
 					// if object implements String, use the result.
-					if stringer, ok := inter.(String); ok {
+					if stringer, ok := inter.(Stringer); ok {
 						s = p.fmt.Fmt_s(stringer.String()).Str();
 						break;
 					}
diff --git a/src/lib/go/parser/parser.go b/src/lib/go/parser/parser.go
index a1effa6d96c..7d18605e4d4 100644
--- a/src/lib/go/parser/parser.go
+++ b/src/lib/go/parser/parser.go
@@ -1914,7 +1914,7 @@ func readSource(src interface{}, err ErrorHandler) []byte {
 		if s != nil {
 			return s.Data();
 		}
-	case io.Read:
+	case io.Reader:
 		var buf io.ByteBuffer;
 		n, os_err := io.Copy(s, &buf);
 		if os_err == nil {
diff --git a/src/lib/http/server.go b/src/lib/http/server.go
index 9b6aa6c414a..5769ced7eea 100644
--- a/src/lib/http/server.go
+++ b/src/lib/http/server.go
@@ -43,7 +43,7 @@ type Conn struct {
 	RemoteAddr string;	// network address of remote side
 	Req *Request;		// current HTTP request
 
-	rwc io.ReadWriteClose;	// i/o connection
+	rwc io.ReadWriteCloser;	// i/o connection
 	buf *bufio.BufReadWrite;	// buffered rwc
 	handler Handler;	// request handler
 	hijacked bool;	// connection has been hijacked by handler
@@ -56,7 +56,7 @@ type Conn struct {
 }
 
 // Create new connection from rwc.
-func newConn(rwc io.ReadWriteClose, raddr string, handler Handler) (c *Conn, err os.Error) {
+func newConn(rwc io.ReadWriteCloser, raddr string, handler Handler) (c *Conn, err os.Error) {
 	c = new(Conn);
 	c.RemoteAddr = raddr;
 	c.handler = handler;
@@ -238,7 +238,7 @@ func (c *Conn) serve() {
 // will not do anything else with the connection.
 // It becomes the caller's responsibility to manage
 // and close the connection.
-func (c *Conn) Hijack() (rwc io.ReadWriteClose, buf *bufio.BufReadWrite, err os.Error) {
+func (c *Conn) Hijack() (rwc io.ReadWriteCloser, buf *bufio.BufReadWrite, err os.Error) {
 	if c.hijacked {
 		return nil, nil, ErrHijacked;
 	}
diff --git a/src/lib/io/io.go b/src/lib/io/io.go
index 5036e326a6e..bb6381099cd 100644
--- a/src/lib/io/io.go
+++ b/src/lib/io/io.go
@@ -16,44 +16,44 @@ import (
 // ErrEOF is the error returned by FullRead and Copyn when they encounter EOF.
 var ErrEOF = os.NewError("EOF")
 
-// Read is the interface that wraps the basic Read method.
-type Read interface {
+// Reader is the interface that wraps the basic Read method.
+type Reader interface {
 	Read(p []byte) (n int, err os.Error);
 }
 
-// Write is the interface that wraps the basic Write method.
-type Write interface {
+// Writer is the interface that wraps the basic Write method.
+type Writer interface {
 	Write(p []byte) (n int, err os.Error);
 }
 
-// Close is the interface that wraps the basic Close method.
-type Close interface {
+// Closer is the interface that wraps the basic Close method.
+type Closer interface {
 	Close() os.Error;
 }
 
 // ReadWrite is the interface that groups the basic Read and Write methods.
-type ReadWrite interface {
-	Read;
-	Write;
+type ReadWriter interface {
+	Reader;
+	Writer;
 }
 
-// ReadClose is the interface that groups the basic Read and Close methods.
-type ReadClose interface {
-	Read;
-	Close;
+// ReadCloser is the interface that groups the basic Read and Close methods.
+type ReadCloser interface {
+	Reader;
+	Closer;
 }
 
-// WriteClose is the interface that groups the basic Write and Close methods.
-type WriteClose interface {
-	Write;
-	Close;
+// WriteCloser is the interface that groups the basic Write and Close methods.
+type WriteCloser interface {
+	Writer;
+	Closer;
 }
 
-// ReadWriteClose is the interface that groups the basic Read, Write and Close methods.
-type ReadWriteClose interface {
-	Read;
-	Write;
-	Close;
+// ReadWriteCloser is the interface that groups the basic Read, Write and Close methods.
+type ReadWriteCloser interface {
+	Reader;
+	Writer;
+	Closer;
 }
 
 // Convert a string to an array of bytes for easy marshaling.
@@ -66,12 +66,12 @@ func StringBytes(s string) []byte {
 }
 
 // WriteString writes the contents of the string s to w, which accepts an array of bytes.
-func WriteString(w Write, s string) (n int, err os.Error) {
+func WriteString(w Writer, s string) (n int, err os.Error) {
 	return w.Write(StringBytes(s))
 }
 
 // FullRead reads r until the buffer buf is full, or until EOF or error.
-func FullRead(r Read, buf []byte) (n int, err os.Error) {
+func FullRead(r Reader, buf []byte) (n int, err os.Error) {
 	n = 0;
 	for n < len(buf) {
 		nn, e := r.Read(buf[n:len(buf)]);
@@ -91,7 +91,7 @@ func FullRead(r Read, buf []byte) (n int, err os.Error) {
 // Convert something that implements Read into something
 // whose Reads are always FullReads
 type fullRead struct {
-	r	Read;
+	r	Reader;
 }
 
 func (fr *fullRead) Read(p []byte) (n int, err os.Error) {
@@ -101,7 +101,7 @@ func (fr *fullRead) Read(p []byte) (n int, err os.Error) {
 
 // MakeFullReader takes r, an implementation of Read, and returns an object
 // that still implements Read but always calls FullRead underneath.
-func MakeFullReader(r Read) Read {
+func MakeFullReader(r Reader) Reader {
 	if fr, ok := r.(*fullRead); ok {
 		// already a fullRead
 		return r
@@ -111,7 +111,7 @@ func MakeFullReader(r Read) Read {
 
 // Copy n copies n bytes (or until EOF is reached) from src to dst.
 // It returns the number of bytes copied and the error, if any.
-func Copyn(src Read, dst Write, n int64) (written int64, err os.Error) {
+func Copyn(src Reader, dst Writer, n int64) (written int64, err os.Error) {
 	buf := make([]byte, 32*1024);
 	for written < n {
 		l := len(buf);
@@ -147,7 +147,7 @@ func Copyn(src Read, dst Write, n int64) (written int64, err os.Error) {
 
 // Copy copies from src to dst until EOF is reached.
 // It returns the number of bytes copied and the error, if any.
-func Copy(src Read, dst Write) (written int64, err os.Error) {
+func Copy(src Reader, dst Writer) (written int64, err os.Error) {
 	buf := make([]byte, 32*1024);
 	for {
 		nr, er := src.Read(buf);
diff --git a/src/lib/io/pipe.go b/src/lib/io/pipe.go
index 446ec69bb4b..5f9e7a488c0 100644
--- a/src/lib/io/pipe.go
+++ b/src/lib/io/pipe.go
@@ -170,15 +170,15 @@ func (w *pipeWrite) finish() {
 }
 
 // Pipe creates a synchronous in-memory pipe.
-// Used to connect code expecting an io.Read
-// with code expecting an io.Write.
+// Used to connect code expecting an io.Reader
+// with code expecting an io.Writer.
 //
 // Reads on one end are matched by writes on the other.
 // Writes don't complete until all the data has been
 // written or the read end is closed.  Reads return
 // any available data or block until the next write
 // or the write end is closed.
-func Pipe() (io.ReadClose, io.WriteClose) {
+func Pipe() (io.ReadCloser, io.WriteCloser) {
 	p := new(pipe);
 	p.cr = make(chan []byte, 1);
 	p.cw = make(chan pipeReturn, 1);
diff --git a/src/lib/io/pipe_test.go b/src/lib/io/pipe_test.go
index 3358ef20329..3df66962854 100644
--- a/src/lib/io/pipe_test.go
+++ b/src/lib/io/pipe_test.go
@@ -11,7 +11,7 @@ import (
 	"time";
 )
 
-func checkWrite(t *testing.T, w io.Write, data []byte, c chan int) {
+func checkWrite(t *testing.T, w Writer, data []byte, c chan int) {
 	n, err := w.Write(data);
 	if err != nil {
 		t.Errorf("write: %v", err);
@@ -25,9 +25,9 @@ func checkWrite(t *testing.T, w io.Write, data []byte, c chan int) {
 // Test a single read/write pair.
 func TestPipe1(t *testing.T) {
 	c := make(chan int);
-	r, w := io.Pipe();
+	r, w := Pipe();
 	var buf = make([]byte, 64);
-	go checkWrite(t, w, io.StringBytes("hello, world"), c);
+	go checkWrite(t, w, StringBytes("hello, world"), c);
 	n, err := r.Read(buf);
 	if err != nil {
 		t.Errorf("read: %v", err);
@@ -40,7 +40,7 @@ func TestPipe1(t *testing.T) {
 	w.Close();
 }
 
-func reader(t *testing.T, r io.Read, c chan int) {
+func reader(t *testing.T, r Reader, c chan int) {
 	var buf = make([]byte, 64);
 	for {
 		n, err := r.Read(buf);
@@ -57,7 +57,7 @@ func reader(t *testing.T, r io.Read, c chan int) {
 // Test a sequence of read/write pairs.
 func TestPipe2(t *testing.T) {
 	c := make(chan int);
-	r, w := io.Pipe();
+	r, w := Pipe();
 	go reader(t, r, c);
 	var buf = make([]byte, 64);
 	for i := 0; i < 5; i++ {
@@ -82,7 +82,7 @@ func TestPipe2(t *testing.T) {
 }
 
 // Test a large write that requires multiple reads to satisfy.
-func writer(w io.WriteClose, buf []byte, c chan pipeReturn) {
+func writer(w WriteCloser, buf []byte, c chan pipeReturn) {
 	n, err := w.Write(buf);
 	w.Close();
 	c <- pipeReturn{n, err};
@@ -90,7 +90,7 @@ func writer(w io.WriteClose, buf []byte, c chan pipeReturn) {
 
 func TestPipe3(t *testing.T) {
 	c := make(chan pipeReturn);
-	r, w := io.Pipe();
+	r, w := Pipe();
 	var wdat = make([]byte, 128);
 	for i := 0; i < len(wdat); i++ {
 		wdat[i] = byte(i);
@@ -132,7 +132,7 @@ func TestPipe3(t *testing.T) {
 
 // Test read after/before writer close.
 
-func delayClose(t *testing.T, cl io.Close, ch chan int) {
+func delayClose(t *testing.T, cl Closer, ch chan int) {
 	time.Sleep(1000*1000);	// 1 ms
 	if err := cl.Close(); err != nil {
 		t.Errorf("delayClose: %v", err);
@@ -142,7 +142,7 @@ func delayClose(t *testing.T, cl io.Close, ch chan int) {
 
 func testPipeReadClose(t *testing.T, async bool) {
 	c := make(chan int, 1);
-	r, w := io.Pipe();
+	r, w := Pipe();
 	if async {
 		go delayClose(t, w, c);
 	} else {
@@ -166,13 +166,13 @@ func testPipeReadClose(t *testing.T, async bool) {
 
 func testPipeWriteClose(t *testing.T, async bool) {
 	c := make(chan int, 1);
-	r, w := io.Pipe();
+	r, w := Pipe();
 	if async {
 		go delayClose(t, r, c);
 	} else {
 		delayClose(t, r, c);
 	}
-	n, err := io.WriteString(w, "hello, world");
+	n, err := WriteString(w, "hello, world");
 	<-c;
 	if err != os.EPIPE {
 		t.Errorf("write on closed pipe: %v", err);
diff --git a/src/lib/log/log.go b/src/lib/log/log.go
index 34158c789eb..4a679a839ef 100644
--- a/src/lib/log/log.go
+++ b/src/lib/log/log.go
@@ -38,8 +38,8 @@ const (
 
 // Logger represents an active logging object.
 type Logger struct {
-	out0	io.Write;	// first destination for output
-	out1	io.Write;	// second destination for output; may be nil
+	out0	io.Writer;	// first destination for output
+	out1	io.Writer;	// second destination for output; may be nil
 	prefix string;	// prefix to write at beginning of each line
 	flag int;	// properties
 }
@@ -48,7 +48,7 @@ type Logger struct {
 // destinations to which log data will be written; out1 may be nil.
 // The prefix appears at the beginning of each generated log line.
 // The flag argument defines the logging properties.
-func NewLogger(out0, out1 io.Write, prefix string, flag int) *Logger {
+func NewLogger(out0, out1 io.Writer, prefix string, flag int) *Logger {
 	return &Logger{out0, out1, prefix, flag}
 }
 
diff --git a/src/lib/net/tcpserver_test.go b/src/lib/net/tcpserver_test.go
index 45b15dab498..62b67b6fa2f 100644
--- a/src/lib/net/tcpserver_test.go
+++ b/src/lib/net/tcpserver_test.go
@@ -11,7 +11,7 @@ import (
 	"testing";
 )
 
-func runEcho(fd io.ReadWrite, done chan<- int) {
+func runEcho(fd io.ReadWriter, done chan<- int) {
 	var buf [1024]byte;
 
 	for {
diff --git a/src/lib/tabwriter/tabwriter.go b/src/lib/tabwriter/tabwriter.go
index 9a5c37c3218..8179165bc55 100644
--- a/src/lib/tabwriter/tabwriter.go
+++ b/src/lib/tabwriter/tabwriter.go
@@ -95,7 +95,7 @@ func (b *byteArray) append(s []byte) {
 //
 type Writer struct {
 	// configuration
-	output io.Write;
+	output io.Writer;
 	cellwidth int;
 	padding int;
 	padbytes [8]byte;
@@ -168,7 +168,7 @@ const (
 //				to the tab width in the viewer displaying the result)
 //	flags		formatting control
 //
-func (b *Writer) Init(output io.Write, cellwidth, padding int, padchar byte, flags uint) *Writer {
+func (b *Writer) Init(output io.Writer, cellwidth, padding int, padchar byte, flags uint) *Writer {
 	if cellwidth < 0 {
 		panic("negative cellwidth");
 	}
@@ -485,6 +485,6 @@ func (b *Writer) Write(buf []byte) (written int, err os.Error) {
 // NewWriter allocates and initializes a new tabwriter.Writer.
 // The parameters are the same as for the the Init function.
 //
-func NewWriter(output io.Write, cellwidth, padding int, padchar byte, flags uint) *Writer {
+func NewWriter(output io.Writer, cellwidth, padding int, padchar byte, flags uint) *Writer {
 	return new(Writer).Init(output, cellwidth, padding, padchar, flags)
 }
diff --git a/src/lib/template/format.go b/src/lib/template/format.go
index 64adba5882c..4fb5393b94b 100644
--- a/src/lib/template/format.go
+++ b/src/lib/template/format.go
@@ -16,7 +16,7 @@ import (
 // It is stored under the name "str" and is the default formatter.
 // You can override the default formatter by storing your default
 // under the name "" in your custom formatter map.
-func StringFormatter(w io.Write, value interface{}, format string) {
+func StringFormatter(w io.Writer, value interface{}, format string) {
 	fmt.Fprint(w, value);
 }
 
@@ -27,7 +27,7 @@ var esc_gt = io.StringBytes("&gt;")
 
 // HtmlEscape writes to w the properly escaped HTML equivalent
 // of the plain text data s.
-func HtmlEscape(w io.Write, s []byte) {
+func HtmlEscape(w io.Writer, s []byte) {
 	last := 0;
 	for i, c := range s {
 		if c == '&' || c == '<' || c == '>' {
@@ -47,7 +47,7 @@ func HtmlEscape(w io.Write, s []byte) {
 }
 
 // HtmlFormatter formats arbitrary values for HTML
-func HtmlFormatter(w io.Write, value interface{}, format string) {
+func HtmlFormatter(w io.Writer, value interface{}, format string) {
 	var b io.ByteBuffer;
 	fmt.Fprint(&b, value);
 	HtmlEscape(w, b.Data());
diff --git a/src/lib/template/template.go b/src/lib/template/template.go
index 7519d16f015..b886b31813a 100644
--- a/src/lib/template/template.go
+++ b/src/lib/template/template.go
@@ -93,7 +93,7 @@ const (
 
 // FormatterMap is the type describing the mapping from formatter
 // names to the functions that implement them.
-type FormatterMap map[string] func(io.Write, interface{}, string)
+type FormatterMap map[string] func(io.Writer, interface{}, string)
 
 // Built-in formatters.
 var builtins = FormatterMap {
@@ -158,7 +158,7 @@ type Template struct {
 type state struct {
 	parent	*state;	// parent in hierarchy
 	data	reflect.Value;	// the driver data for this section etc.
-	wr	io.Write;	// where to send output
+	wr	io.Writer;	// where to send output
 	errors	chan os.Error;	// for reporting errors during execute
 }
 
@@ -769,7 +769,7 @@ func (t *Template) Parse(s string) os.Error {
 
 // Execute applies a parsed template to the specified data object,
 // generating output to wr.
-func (t *Template) Execute(data interface{}, wr io.Write) os.Error {
+func (t *Template) Execute(data interface{}, wr io.Writer) os.Error {
 	// Extract the driver data.
 	val := reflect.NewValue(data);
 	errors := make(chan os.Error);
diff --git a/src/lib/template/template_test.go b/src/lib/template/template_test.go
index fb931615ea6..9a81d274c91 100644
--- a/src/lib/template/template_test.go
+++ b/src/lib/template/template_test.go
@@ -54,8 +54,8 @@ func plus1(v interface{}) string {
 	return fmt.Sprint(i + 1);
 }
 
-func writer(f func(interface{}) string) (func(io.Write, interface{}, string)) {
-	return func(w io.Write, v interface{}, format string) {
+func writer(f func(interface{}) string) (func(io.Writer, interface{}, string)) {
+	return func(w io.Writer, v interface{}, format string) {
 		io.WriteString(w, f(v));
 	}
 }
diff --git a/usr/gri/pretty/astprinter.go b/usr/gri/pretty/astprinter.go
index 7cccbdc4848..c45508868f3 100644
--- a/usr/gri/pretty/astprinter.go
+++ b/usr/gri/pretty/astprinter.go
@@ -69,31 +69,31 @@ func hasExportedNames(names []*ast.Ident) bool {
 // initializing an AST Printer. It is used to print tokens.
 //
 type TokenPrinter interface {
-	PrintLit(w io.Write, tok token.Token, value []byte);
-	PrintIdent(w io.Write, value string);
-	PrintToken(w io.Write, token token.Token);
-	PrintComment(w io.Write, value []byte);
+	PrintLit(w io.Writer, tok token.Token, value []byte);
+	PrintIdent(w io.Writer, value string);
+	PrintToken(w io.Writer, token token.Token);
+	PrintComment(w io.Writer, value []byte);
 }
 
 
 type defaultPrinter struct {}
 
-func (p defaultPrinter) PrintLit(w io.Write, tok token.Token, value []byte) {
+func (p defaultPrinter) PrintLit(w io.Writer, tok token.Token, value []byte) {
 	w.Write(value);
 }
 
 
-func (p defaultPrinter) PrintIdent(w io.Write, value string) {
+func (p defaultPrinter) PrintIdent(w io.Writer, value string) {
 	fmt.Fprint(w, value);
 }
 
 
-func (p defaultPrinter) PrintToken(w io.Write, token token.Token) {
+func (p defaultPrinter) PrintToken(w io.Writer, token token.Token) {
 	fmt.Fprint(w, token.String());
 }
 
 
-func (p defaultPrinter) PrintComment(w io.Write, value []byte) {
+func (p defaultPrinter) PrintComment(w io.Writer, value []byte) {
 	w.Write(value);
 }
 
@@ -123,7 +123,7 @@ const (
 
 type Printer struct {
 	// output
-	text io.Write;
+	text io.Writer;
 
 	// token printing
 	tprinter TokenPrinter;
@@ -171,7 +171,7 @@ func (P *Printer) nextComments() {
 }
 
 
-func (P *Printer) Init(text io.Write, tprinter TokenPrinter, comments []*ast.Comment, html bool) {
+func (P *Printer) Init(text io.Writer, tprinter TokenPrinter, comments []*ast.Comment, html bool) {
 	// writers
 	P.text = text;
 
@@ -435,7 +435,7 @@ func (P *Printer) Error(pos token.Position, tok token.Token, msg string) {
 }
 
 
-// An astPrinter implements io.Write.
+// An astPrinter implements io.Writer.
 // TODO this is not yet used.
 func (P *Printer) Write(p []byte) (n int, err os.Error) {
 	// TODO
diff --git a/usr/gri/pretty/comment.go b/usr/gri/pretty/comment.go
index 1025856c4bd..82a7cdd7a70 100644
--- a/usr/gri/pretty/comment.go
+++ b/usr/gri/pretty/comment.go
@@ -53,7 +53,7 @@ var (
 
 // Escape comment text for HTML.
 // Also, turn `` into &ldquo; and '' into &rdquo;.
-func commentEscape(w io.Write, s []byte) {
+func commentEscape(w io.Writer, s []byte) {
 	last := 0;
 	for i := 0; i < len(s)-1; i++ {
 		if s[i] == s[i+1] && (s[i] == '`' || s[i] == '\'') {
@@ -137,7 +137,7 @@ func unindent(block [][]byte) {
 //
 // TODO(rsc): I'd like to pass in an array of variable names []string
 // and then italicize those strings when they appear as words.
-func ToHtml(w io.Write, s []byte) {
+func ToHtml(w io.Writer, s []byte) {
 	inpara := false;
 
 	/* TODO(rsc): 6g cant generate code for these
diff --git a/usr/gri/pretty/format.go b/usr/gri/pretty/format.go
index 960b5c58fde..72673419137 100644
--- a/usr/gri/pretty/format.go
+++ b/usr/gri/pretty/format.go
@@ -44,7 +44,7 @@ var (
 // Format representation
 
 type (
-	Formatter func(w io.Write, value interface{}, name string) bool;
+	Formatter func(w io.Writer, value interface{}, name string) bool;
 	FormatterMap map[string]Formatter;
 )
 
@@ -476,7 +476,7 @@ func readSource(src interface{}) ([]byte, os.Error) {
 		}
 		return s.Data(), nil;
 
-	case io.Read:
+	case io.Reader:
 		var buf io.ByteBuffer;
 		n, err := io.Copy(s, &buf);
 		if err != nil {
@@ -654,7 +654,7 @@ func percentCount(s []byte) int {
 }
 
 
-func rawPrintf(w io.Write, format []byte, value reflect.Value) {
+func rawPrintf(w io.Writer, format []byte, value reflect.Value) {
 	// TODO find a better way to do this
 	x := value.Interface();
 	switch percentCount(format) {
@@ -724,7 +724,7 @@ func (ps *state) outdent() {
 }
 
 
-func (ps *state) printIndented(w io.Write, s []byte) {
+func (ps *state) printIndented(w io.Writer, s []byte) {
 	// replace each '\n' with the indent + '\n'
 	i0 := 0;
 	for i := 0; i < len(s); i++ {
@@ -738,7 +738,7 @@ func (ps *state) printIndented(w io.Write, s []byte) {
 }
 
 
-func (ps *state) printf(w io.Write, format []byte, value reflect.Value) {
+func (ps *state) printf(w io.Writer, format []byte, value reflect.Value) {
 	if len(ps.indent_widths) == 0 {
 		// no indentation
 		rawPrintf(w, format, value);
@@ -751,10 +751,10 @@ func (ps *state) printf(w io.Write, format []byte, value reflect.Value) {
 }
 
 
-func (ps *state) print(w io.Write, fexpr expr, value reflect.Value, index, level int) bool
+func (ps *state) print(w io.Writer, fexpr expr, value reflect.Value, index, level int) bool
 
 // Returns true if a non-empty field value was found.
-func (ps *state) print0(w io.Write, fexpr expr, value reflect.Value, index, level int) bool {
+func (ps *state) print0(w io.Writer, fexpr expr, value reflect.Value, index, level int) bool {
 	if fexpr == nil {
 		return true;
 	}
@@ -917,7 +917,7 @@ func printTrace(indent int, format string, a ...) {
 }
 
 
-func (ps *state) print(w io.Write, fexpr expr, value reflect.Value, index, level int) bool {
+func (ps *state) print(w io.Writer, fexpr expr, value reflect.Value, index, level int) bool {
 	if *trace {
 		printTrace(level, "%v, %d {\n", fexpr, /*value.Interface(), */index);
 	}
@@ -936,7 +936,7 @@ func (ps *state) print(w io.Write, fexpr expr, value reflect.Value, index, level
 // Fprint formats each argument according to the format f
 // and writes to w.
 //
-func (f Format) Fprint(w io.Write, args ...) {
+func (f Format) Fprint(w io.Writer, args ...) {
 	value := reflect.NewValue(args).(reflect.StructValue);
 	for i := 0; i < value.Len(); i++ {
 		fld := value.Field(i);
diff --git a/usr/gri/pretty/godoc.go b/usr/gri/pretty/godoc.go
index 1d4eb5af336..22b1bb52eaf 100644
--- a/usr/gri/pretty/godoc.go
+++ b/usr/gri/pretty/godoc.go
@@ -97,7 +97,7 @@ func isDir(name string) bool {
 }
 
 
-func makeTabwriter(writer io.Write) *tabwriter.Writer {
+func makeTabwriter(writer io.Writer) *tabwriter.Writer {
 	padchar := byte(' ');
 	if *usetabs {
 		padchar = '\t';
@@ -255,7 +255,7 @@ func toText(x interface{}) []byte {
 
 
 // Template formatter for "html" format.
-func htmlFmt(w io.Write, x interface{}, format string) {
+func htmlFmt(w io.Writer, x interface{}, format string) {
 	// Can do better than text in some cases.
 	switch v := x.(type) {
 	case ast.Decl:
@@ -277,13 +277,13 @@ func htmlFmt(w io.Write, x interface{}, format string) {
 
 
 // Template formatter for "html-comment" format.
-func htmlCommentFmt(w io.Write, x interface{}, format string) {
+func htmlCommentFmt(w io.Writer, x interface{}, format string) {
 	comment.ToHtml(w, toText(x));
 }
 
 
 // Template formatter for "" (default) format.
-func textFmt(w io.Write, x interface{}, format string) {
+func textFmt(w io.Writer, x interface{}, format string) {
 	w.Write(toText(x));
 }
 
@@ -292,7 +292,7 @@ func textFmt(w io.Write, x interface{}, format string) {
 // Writes out "/" if the os.Dir argument is a directory.
 var slash = io.StringBytes("/");
 
-func dirSlashFmt(w io.Write, x interface{}, format string) {
+func dirSlashFmt(w io.Writer, x interface{}, format string) {
 	d := x.(os.Dir);	// TODO(rsc): want *os.Dir
 	if d.IsDirectory() {
 		w.Write(slash);
diff --git a/usr/gri/pretty/pretty.go b/usr/gri/pretty/pretty.go
index ffe2c0e2e89..5a27d40207a 100644
--- a/usr/gri/pretty/pretty.go
+++ b/usr/gri/pretty/pretty.go
@@ -61,7 +61,7 @@ func readFile(filename string) ([]byte, os.Error) {
 
 
 // TODO(gri) move this function into tabwriter.go? (also used in godoc)
-func makeTabwriter(writer io.Write) *tabwriter.Writer {
+func makeTabwriter(writer io.Writer) *tabwriter.Writer {
 	padchar := byte(' ');
 	if *usetabs {
 		padchar = '\t';
@@ -94,17 +94,17 @@ func (h *ErrorHandler) Error(pos token.Position, msg string) {
 }
 
 
-func isValidPos(w io.Write, value interface{}, name string) bool {
+func isValidPos(w io.Writer, value interface{}, name string) bool {
 	return value.(token.Position).Line > 0;
 }
 
 
-func isSend(w io.Write, value interface{}, name string) bool {
+func isSend(w io.Writer, value interface{}, name string) bool {
 	return value.(ast.ChanDir) & ast.SEND != 0;
 }
 
 
-func isRecv(w io.Write, value interface{}, name string) bool {
+func isRecv(w io.Writer, value interface{}, name string) bool {
 	return value.(ast.ChanDir) & ast.RECV != 0;
 }