diff --git a/client.go b/client.go
index ac76dd3..d045b3e 100644
--- a/client.go
+++ b/client.go
@@ -11,25 +11,27 @@ import (
 
 func (c *Client) setNick(nick string) {
 	if c.nick != "" {
-		delete(c.server.clientMap, c.nick)
+		oldNickKey := strings.ToLower(c.nick)
+		delete(c.server.clientMap, oldNickKey)
 		for _, channel := range c.channelMap {
-			delete(channel.clientMap, c.nick)
+			delete(channel.clientMap, oldNickKey)
 		}
 	}
 
 	//Set up new nick
 	oldNick := c.nick
 	c.nick = nick
-	c.server.clientMap[c.nick] = c
+	nickKey := strings.ToLower(c.nick)
+	c.server.clientMap[nickKey] = c
 
 	clients := make([]string, 0, 100)
 
 	for _, channel := range c.channelMap {
-		channel.clientMap[c.nick] = c
+		channel.clientMap[nickKey] = c
 
 		//Collect list of client nicks who can see us
-		for client := range channel.clientMap {
-			clients = append(clients, client)
+		for _, client := range channel.clientMap {
+			clients = append(clients, client.nick)
 		}
 	}
 
@@ -42,7 +44,7 @@ func (c *Client) setNick(nick string) {
 		}
 		prevNick = nick
 
-		client, exists := c.server.clientMap[nick]
+		client, exists := c.server.clientMap[strings.ToLower(nick)]
 		if exists {
 			client.reply(rplNickChange, oldNick, c.nick)
 		}
@@ -50,16 +52,17 @@ func (c *Client) setNick(nick string) {
 }
 
 func (c *Client) joinChannel(channelName string) {
-	channel, exists := c.server.channelMap[channelName]
+	channelKey := strings.ToLower(channelName)
+	channel, exists := c.server.channelMap[channelKey]
 	if exists == false {
 		channel = &Channel{name: channelName,
 			topic:     "",
 			clientMap: make(map[string]*Client)}
-		c.server.channelMap[channelName] = channel
+		c.server.channelMap[channelKey] = channel
 	}
 
-	channel.clientMap[c.nick] = c
-	c.channelMap[channelName] = channel
+	channel.clientMap[strings.ToLower(c.nick)] = c
+	c.channelMap[channelKey] = channel
 
 	for _, client := range channel.clientMap {
 		client.reply(rplJoin, c.nick, channelName)
@@ -72,15 +75,16 @@ func (c *Client) joinChannel(channelName string) {
 	}
 
 	nicks := make([]string, 0, 100)
-	for nick := range channel.clientMap {
-		nicks = append(nicks, nick)
+	for _, client := range channel.clientMap {
+		nicks = append(nicks, client.nick)
 	}
 
 	c.reply(rplNames, channelName, strings.Join(nicks, " "))
 }
 
 func (c *Client) partChannel(channelName string) {
-	channel, exists := c.server.channelMap[channelName]
+	channelKey := strings.ToLower(channelName)
+	channel, exists := c.server.channelMap[channelKey]
 	if exists == false {
 		return
 	}
@@ -90,8 +94,11 @@ func (c *Client) partChannel(channelName string) {
 		client.reply(rplPart, c.nick, channelName)
 	}
 
-	delete(channel.clientMap, c.nick)
-	delete(c.channelMap, channelName)
+	delete(channel.clientMap, strings.ToLower(c.nick))
+
+	if len(channel.clientMap) == 0 {
+		delete(c.channelMap, channelKey)
+	}
 }
 
 func (c *Client) disconnect() {
@@ -171,7 +178,7 @@ func (c *Client) clientThread() {
 			c.partChannel(channelName)
 		}
 
-		delete(c.server.clientMap, c.nick)
+		delete(c.server.clientMap, strings.ToLower(c.nick))
 
 		c.connection.Close()
 	}()
@@ -237,8 +244,7 @@ func (c *Client) writeThread(signalChan chan signalCode, outputChan chan string)
 			line := []byte(fmt.Sprintf("%s\r\n", output))
 
 			c.connection.SetWriteDeadline(time.Now().Add(time.Second * 30))
-			_, err := c.connection.Write(line)
-			if err != nil {
+			if _, err := c.connection.Write(line); err != nil {
 				c.disconnect()
 				return
 			}
diff --git a/server.go b/server.go
index 9f02b8a..8d7dbc1 100644
--- a/server.go
+++ b/server.go
@@ -11,7 +11,7 @@ import (
 
 var (
 	nickRegexp    = regexp.MustCompile(`^[a-zA-Z\[\]_^{|}][a-zA-Z0-9\[\]_^{|}]*$`)
-	channelRegexp = regexp.MustCompile(`^#[a-z0-9_\-]+$`)
+	channelRegexp = regexp.MustCompile(`^#[a-zA-Z0-9_\-]+$`)
 )
 
 func NewServer() *Server {
@@ -68,7 +68,7 @@ func (s *Server) handleEvent(e Event) {
 			return
 		}
 
-		if _, exists := s.clientMap[newNick]; exists {
+		if _, exists := s.clientMap[strings.ToLower(newNick)]; exists {
 			e.client.reply(errNickInUse, newNick)
 			return
 		}
@@ -149,8 +149,8 @@ func (s *Server) handleEvent(e Event) {
 
 		message := strings.Join(args[1:], " ")
 
-		channel, chanExists := s.channelMap[args[0]]
-		client, clientExists := s.clientMap[args[0]]
+		channel, chanExists := s.channelMap[strings.ToLower(args[0])]
+		client, clientExists := s.clientMap[strings.ToLower(args[0])]
 
 		if chanExists {
 			for _, c := range channel.clientMap {
@@ -183,7 +183,7 @@ func (s *Server) handleEvent(e Event) {
 			return
 		}
 
-		channel, exists := s.channelMap[args[0]]
+		channel, exists := s.channelMap[strings.ToLower(args[0])]
 		if exists == false {
 			e.client.reply(errNoSuchNick, args[0])
 			return
@@ -232,7 +232,7 @@ func (s *Server) handleEvent(e Event) {
 			chanList := make([]string, 0, len(channels))
 
 			for _, channelName := range channels {
-				if channel, exists := s.channelMap[channelName]; exists {
+				if channel, exists := s.channelMap[strings.ToLower(channelName)]; exists {
 					listItem := fmt.Sprintf("%s %d :%s", channelName, len(channel.clientMap), channel.topic)
 					chanList = append(chanList, listItem)
 				}
@@ -284,7 +284,7 @@ func (s *Server) handleEvent(e Event) {
 
 		nick := args[0]
 
-		if client, exists := s.clientMap[nick]; exists {
+		if client, exists := s.clientMap[strings.ToLower(nick)]; exists {
 			client.reply(rplKill, "An operator has disconnected you.")
 			client.disconnect()
 		} else {