Cbox Chat

Get a Cbox and add a new dimension of interaction to your website or blog. Cbox is a unique chat and messaging application that brings the best features of traditional chat and tagging systems to the social web. And the best part – Cbox Basic is completely free.

http://www.cbox.ws/

Chatango

You can create your own chat room, a Chatango group for your web page or blog. This is a public chat, and recent messages stay in the group history. As a group owner, you can block people from your group, delete messages from it, ban words, and make group moderators. A Chatango group chat in a web site, e.g. blogger.com.

http://chatango.com/

FCChat

Enhance your internet forum, blog, social networking site, or chat site with this plugin. It’s a great accessory to any internet community. This powerful and innovative technology equips your site with full featured, real time chatting capabilities. It allows your visitors to participate in group and private chats, send instant messages, and share pictures, while simultaneously enjoying the other features of your site.

The chat widget is easy to install, and integrates seamlessly into an existing site. In addition, it comes with a detailed administration and moderation system. Experience Fastcat Chat for yourself by trying the demo at the top of the page.

http://www.fastcatsoftware.com/

JWChat

JWChat is a full featured, web-based Jabber client. Written using AJAX technology it relies on JavaScript and HTML at the client-side only. It supports basicm jabber instant messaging, roster management and group chats based on the MUC protocol.

JWChat is an advanced instant messenger (IM) just like AIM, MSN Messenger, Yahoo! Messenger or ICQ. This means you can manage your contacts, communicate with other users in 1:1 chat sessions or join a group chat room for collaborative communication. Unlike other IMs you can use this with your web browser without having to install any additional software at all.

http://blog.jwchat.org/jwchat/

Meebo

Meebo Me lets you chat with anyone who comes to your blog or Web page. Visitors show up in your Meebo buddylist so you can strike up a conversation, answer questions, or just keep tabs on guests. Publish your online status so friends can see if you’re available when they visit your site.

http://www.meebo.com/

Mibew Messenger

Mibew Messenger (also known as Open Web Messenger) is an open-source live support application written in PHP and MySQL. It enables one-on-one chat assistance in real-time directly from your website.You should place the button of Web Messenger at your site. Your visitors click the button and chat with your operators who help them.

http://mibew.org/

phpFreeChat

phpFreeChat is a free, simple to install, fast, customizable and multi languages chat that uses a simple filesystem for message and nickname storage. It uses AJAX to smoothly refresh (no flicker) and display the chat zone and the nickname zone.

It supports multi-rooms (/join), private messages, moderation (/kick, /ban), customized themes based on CSS and plugins systems that allows you to write your own storage routines (ex: Mysql, IRC backends …), and you own chat commands

http://www.phpfreechat.net/