diff --git a/goircd.go b/goircd.go
index 822d34bd..ab968579 100644
--- a/goircd.go
+++ b/goircd.go
@@ -1,5 +1,5 @@
 package main
-// http://tools.ietf.org/html/rfc1459
+// http://tools.ietf.org/html/rfc2812
 
 import (
 	"irc"
@@ -7,5 +7,5 @@ import (
 
 func main() {
 	server := irc.NewServer()
-	server.Listen(":6697")
+	server.Listen(":6667")
 }
diff --git a/src/irc/client.go b/src/irc/client.go
index e5370924..245b75e2 100644
--- a/src/irc/client.go
+++ b/src/irc/client.go
@@ -1,28 +1,47 @@
 package irc
 
 import (
+	"log"
 	"net"
+	"strings"
 )
 
+type Message struct {
+	command string
+	args    string
+	client  *Client
+}
 
 type Client struct {
-	conn net.Conn
-	ch chan Message
+	addr       net.Addr
+	send       chan string
+	recv       chan string
+	username   string
+	realname   string
+	nick       string
 }
 
 func NewClient(conn net.Conn) *Client {
-	return &Client{conn, NewMessageChan(NewStringChan(conn))}
+	client := new(Client)
+	client.addr = conn.RemoteAddr()
+	client.send = StringWriteChan(conn)
+	client.recv = StringReadChan(conn)
+	return client
 }
 
-// Write messages from the client to the server.
-func (c *Client) Communicate(server chan Message) {
-	for message := range c.ch {
-		message.client = c
-		server <- message
+// Adapt `chan string` to a `chan Message`.
+func (c *Client) Communicate(server *Server) {
+	go func() {
+		for str := range c.recv {
+			parts := strings.SplitN(str, " ", 2)
+			server.Send(Message{parts[0], parts[1], c})
+		}
+	}()
+}
+
+func (c *Client) Send(lines ...string) {
+	for _, line := range lines {
+		log.Printf("C <- S: %s", line)
+		c.send <- line
 	}
-	c.Close()
-}
-
-func (c *Client) Close() {
-	c.conn.Close()
 }
diff --git a/src/irc/net.go b/src/irc/net.go
index fcbfa874..360dcd02 100644
--- a/src/irc/net.go
+++ b/src/irc/net.go
@@ -3,43 +3,42 @@ package irc
 import (
 	"bufio"
 	"log"
+	"strings"
 	"net"
 )
 
 // Adapt `net.Conn` to a `chan string`.
-func NewStringChan(conn net.Conn) chan string {
+func StringReadChan(conn net.Conn) chan string {
 	ch := make(chan string)
-	rw := bufio.NewReadWriter(bufio.NewReader(conn), bufio.NewWriter(conn))
-
-	done := make(chan bool)
-	go func() {
-		<- done
-		close(ch)
-	}()
-
-	// conn -> ch
+	reader := bufio.NewReader(conn)
 	go func() {
 		for {
-			line, err := rw.ReadString('\n')
+			line, err := reader.ReadString('\n')
+			if (line != "") {
+				ch <- strings.TrimSpace(line)
+			}
 			if err != nil {
-				log.Print("StringChan[read]: %v", err)
+				log.Print("StringReadChan[read]: ", err)
 				break
 			}
-			ch <- line
 		}
-		done <- true
+		close(ch)
 	}()
+	return ch
+}
 
-	// ch -> conn
+func StringWriteChan(conn net.Conn) chan string {
+	ch := make(chan string)
+	writer := bufio.NewWriter(conn)
 	go func() {
 		for str := range ch {
-			if _, err := rw.WriteString(str + "\r\n"); err != nil {
-				log.Print("StringChan[write]: %v", err)
+			if _, err := writer.WriteString(str + "\r\n"); err != nil {
+				log.Print("StringWriteChan[write]: ", err)
 				break
 			}
-			rw.Flush()
+			writer.Flush()
 		}
-		done <- true
+		close(ch)
 	}()
 
 	return ch
diff --git a/src/irc/protocol.go b/src/irc/protocol.go
index f5699040..071601be 100644
--- a/src/irc/protocol.go
+++ b/src/irc/protocol.go
@@ -1,43 +1,107 @@
 package irc
 
 import (
+	"fmt"
 )
 
-type Message struct {
-	line string
-	client *Client
+const (
+	VERSION = "goircd-1"
+)
+
+const (
+	RPL_WELCOME  = "001"
+	RPL_YOURHOST = "002"
+	RPL_CREATED  = "003"
+	RPL_MYINFO   = "004"
+	RPL_NONE     = "300"
+)
+
+func ReplyWelcome(nick string, user string, host string) string {
+	return fmt.Sprintf("%s %s Welcome to the Internet Relay Network %s!%s@%s", RPL_WELCOME, nick, nick, user, host)
 }
 
-func (m *Message) Encode() string {
-	return m.line
+func ReplyYourHost(nick string, server string) string {
+	return fmt.Sprintf("%s %s Your host is %s, running version %s", RPL_YOURHOST, nick, server, VERSION)
+}
+
+func ReplyCreated(nick string, created string) string {
+	return fmt.Sprintf("%s %s This server was created %s", RPL_CREATED, nick, created)
+}
+
+func ReplyMyInfo(nick string, servername string) string {
+	return fmt.Sprintf("%s %s %s %s <user modes> <channel modes>", RPL_MYINFO, nick, servername, VERSION)
+}
+
+const (
+	ERR_NOSUCHNICK       = "401"
+	ERR_NOSUCHSERVER     = "402"
+	ERR_NOSUCHCHANNEL    = "403"
+	ERR_UNKNOWNCOMMAND   = "421"
+	ERR_NICKNAMEINUSE    = "433"
+	ERR_NEEDMOREPARAMS   = "461"
+	ERR_ALREADYREGISTRED = "462"
+	ERR_USERSDONTMATCH   = "502"
+)
+
+func ErrAlreadyRegistered(nick string) string {
+	return fmt.Sprintf("%s %s :You may not reregister", ERR_ALREADYREGISTRED, nick)
+}
+
+func ErrNickNameInUse(nick string) string {
+	return fmt.Sprintf("%s %s :Nickname is already in use", ERR_NICKNAMEINUSE, nick)
+}
+
+func ErrUnknownCommand(nick string, command string) string {
+	return fmt.Sprintf("%s %s %s :Unknown command", ERR_UNKNOWNCOMMAND, nick, command)
 }
 
 
-// Adapt `chan string` to a `chan Message`.
-func NewMessageChan(strch chan string) chan Message {
-	msgch := make(chan Message)
+const (
+	RE_PASS     = "(?P<password>\\S+)"
+	RE_NICK     = "(?P<nickname>\\S+)"
+	RE_USER     = "(?P<user>\\S+) (?P<mode>\\d) (?:\\S+) :(?P<realname>.+)"
+	RE_OPER     = "(?P<name>\\S+) (?P<password>\\S+)"
+	RE_MODE     = "(?P<nickname>\\S+)(?: (?P<mode>[-+][iwroOs]+))*"
+	RE_SERVICE  = "(?P<nickname>\\S+) (?P<reserved1>\\S+) (?P<distribution>\\S+) (?P<type>\\S+) (?P<reserved2>\\S+) :(?P<info>.+)"
+	RE_QUIT     = "(?P<message>.*)"
+	RE_SQUIT    = "(?P<server>\\S+) :(?P<comment>.+)"
+	RE_JOIN     = "0|(?:(?P<channels>\\S+(?:,\\S+)*)(?: (?P<keys>\\S+(?:,\\S+)*))?)"
+	RE_PART     = "(?P<channels>\\S+(?:,\\S+)*)(?: :(?P<message>.+))?"
+	RE_MODE_CH  = "(?P<channel>\\S+)(?: (?P<mode>[-+][iwroOs]+))*" // XXX incomplete
+	RE_TOPIC    = "(?P<channel>\\S+)(?: :(?P<topic>.+))?"
+	RE_NAMES    = "(?:(?P<channels>\\S+(?:,\\S+)*)(?: (?P<target>\\S+))?)?"
+	RE_LIST     = "(?:(?P<channels>\\S+(?:,\\S+)*)(?: (?P<target>\\S+))?)?"
+	RE_INVITE   = "(?P<nickname>\\S+) (?P<channel>\\S+)"
+	RE_KICK     = "(?P<channels>\\S+(?:,\\S+)*) (?P<users>\\S+(?:,\\S+))(?: :(?P<comment>.+))?"
+	RE_PRIVMSG  = "(?P<target>\\S+) :(?P<text>.+)"
+	RE_NOTICE   = "(?P<target>\\S+) :(?P<text>.+)"
+	RE_MOTD     = "(?P<target>\\S+)?"
+	RE_LUSERS   = "(?:(?P<mask>\\S+)(?: (?P<target>\\S+))?)?"
+	RE_VERSION  = "(?P<target>\\S+)?"
+	RE_STATS    = "(?:(?P<query>\\S+)(?: (?P<target>\\S+))?)?"
+	RE_LINKS    = "(?:(?P<remote>\\S+) )?(?P<mask>\\S+)"
+	RE_TIME     = "(?P<target>\\S+)?"
+	RE_CONNECT  = "(?P<target>\\S+) (?P<port>\\d+)(?: (?P<remote>\\S+))?"
+	RE_TRACE    = "(?P<target>\\S+)?"
+	RE_ADMIN    = "(?P<target>\\S+)?"
+	RE_INFO     = "(?P<target>\\S+)?"
+	RE_SERVLIST = "" // XXX
+	RE_SQUERY   = "" // XXX
+	RE_WHO      = "" // XXX
+	RE_WHOIS    = "" // XXX
+	RE_WHOWAS   = "" // XXX
+	RE_KILL     = "(?P<nickname>\\S+) :(?P<comment>.+)"
+	RE_PING     = "(?P<server1>\\S+)(?: (?P<server2>\\S+))?"
+	RE_PONG     = "(?P<server1>\\S+)(?: (?P<server2>\\S+))?"
+	RE_ERROR    = ":(?P<error>.+)"
+	RE_AWAY     = ":(?P<text>.+)"
+	RE_REHASH   = ""
+	RE_DIE      = ""
+	RE_RESTART  = ""
+	RE_SUMMON   = "(?P<user>\\S+)(?: (?P<target>\\S+)(?: (?P<channel>\\S+))?)?"
+	RE_USERS    = "(?P<target>\\S+)?"
+	RE_WALLOPS  = ":(?P<text>.+)"
+	RE_USERHOST = "(?P<nicknames>\\S+(?: \\S+)*)"
+	RE_ISON     = "(?P<nicknames>\\S+(?: \\S+)*)"
+)
 
-	done := make(chan bool)
-	go func() {
-		<- done
-		close(msgch)
-	}()
-
-	// str -> msg
-	go func() {
-		for str := range strch {
-			msgch <- Message{str, nil}
-		}
-		done <- true
-	}()
-
-	// msg -> str
-	go func() {
-		for message := range msgch {
-			strch <- message.Encode()
-		}
-		done <- true
-	}()
-
-	return msgch
-}
diff --git a/src/irc/server.go b/src/irc/server.go
index 39ca7bba..2085f647 100644
--- a/src/irc/server.go
+++ b/src/irc/server.go
@@ -3,14 +3,17 @@ package irc
 import (
 	"log"
 	"net"
+	"strings"
 )
 
 type Server struct {
 	ch chan Message
+	users map[string]*Client
+	nicks map[string]*Client
 }
 
 func NewServer() *Server {
-	server := Server{make(chan Message)}
+	server := Server{make(chan Message), make(map[string]*Client), make(map[string]*Client)}
 	go server.Receive()
 	return &server
 }
@@ -18,27 +21,69 @@ func NewServer() *Server {
 func (s *Server) Listen(addr string) {
 	listener, err := net.Listen("tcp", addr)
 	if err != nil {
-		log.Fatal("Server.Listen: %v", err)
+		log.Fatal("Server.Listen: ", err)
 	}
 
 	for {
 		conn, err := listener.Accept()
 		if err != nil {
-			log.Print("Server.Listen: %v", err)
+			log.Print("Server.Listen: ", err)
 			continue
 		}
-		client := NewClient(conn)
-		go client.Communicate(s.ch)
+		go NewClient(conn).Communicate(s)
 	}
 }
 
 func (s *Server) Receive() {
 	for message := range s.ch {
-		log.Print("Server.Receive: %v", message.line)
-		message.client.ch <- Message{"pong: " + message.line, nil}
+		log.Printf("C -> S: %s %s", message.command, message.args)
+		switch message.command {
+		case "PING":
+			message.client.Send("PONG")
+		case "PASS":
+			s.PassCommand(message.client, message.args)
+		case "USER":
+			s.UserCommand(message.client, message.args)
+		case "NICK":
+			s.NickCommand(message.client, message.args)
+		default:
+			message.client.Send(ErrUnknownCommand(message.client.nick, message.command))
+		}
 	}
 }
 
-func (s *Server) Close() {
-	close(s.ch)
+func (s *Server) Send(m Message) {
+	s.ch <- m
+}
+
+// commands
+
+func (s *Server) PassCommand(c *Client, args string) {
+}
+
+func (s *Server) UserCommand(c *Client, args string) {
+	parts := strings.SplitN(args, " ", 4)
+	username, _, _, realname := parts[0], parts[1], parts[2], parts[3]
+	if s.users[username] != nil {
+		c.Send(ErrAlreadyRegistered(c.nick))
+		return
+	}
+	c.username, c.realname = username, realname
+	s.users[username] = c
+	if c.nick != "" {
+		c.Send(
+			ReplyWelcome(c.nick, c.username, "localhost"),
+			ReplyYourHost(c.nick, "irc.jlatt.com"),
+			ReplyCreated(c.nick, "2012/04/07"),
+			ReplyMyInfo(c.nick, "irc.jlatt.com"))
+	}
+}
+
+func (s *Server) NickCommand(c *Client, nick string) {
+	if s.nicks[nick] != nil {
+		c.Send(ErrNickNameInUse(nick))
+		return
+	}
+	c.nick = nick
+	s.nicks[nick] = c
 }