wozozobot.php

<?php
require_once 'Net/IRC/Client.php';

class WozozoBot extends Net_IRC_Client
{
    protected function on_privmsg($m) {
        list($prefix, $msg) = $m->params;
        if ($msg == 'wozozo')
            $this->privmsg($prefix, 'yudoufu');
    }
}

$bot = new WozozoBot('localhost', 6667, array('user' => 'wozozo2', 'nick' => 'wozozo2'));
$bot->connect();