Shout it  

This ShoutBox is loaded with features: Easy Setup - Smilies - Swear Filter - Flood Control - Everything is wrapped in CSS - Recognizes URLS - Logs IPs - Admin can Ban/UnBan IPs - Auto Deletion of Old Entries an more.

Hosting Requirements: Unix/Linux, Windows
Database: MySQL
Price: Free

   txtShout  

A shoutbox / chatterbox / tagboard that works entirely from a plain-text file (no database). Because of this, it's easy to set up and runs fast. Features: Simple, fast design - Easy to use - Easy integration and style customisation - Smilie parser (30 smilies included) - URL / email address auto-hyperlinking - Supports all timezones - Profanity filter - Smart forced linebreaking.

Hosting Requirements: PHP4
Price: Free

   PhpTocAim  

PhpTocAim is a PHP class that can be used to connect to AIM (AOL Instant Messenger) servers using the TOC protocal to do normal tasks such as receiving IMs, sending IMs, joining chats and the such. PhpTocAim is very easy to use, and has inbuilt methods and even event handling. The login and basic actions / events are covered. PhpTocAim can be used to make a web based AIM client (through the web browser or maybe Flash), an intelligent bot, an AIM based game, and anything you think of!

Hosting Requirements: PHP 4.1+
Price: Free (GPL)

   Liquid Frog  

Frog Tag is a free Tag Board or Shout Box. It's very simple to set up and very easy to use requiring no database but running instead on a flat file. It has many useful features including easy configuration for colors via a cascading style sheet, users can enter their web site address and the script changes it to a clickable link that opens in a new window, support for filtering out bad words and it can be used in both PHP and HTML pages. You can also define the number of shouts to be shown and the maximum length of each shout.

Hosting Requirements: Unix
Price: Free

   Tagified  

Tagified is a clean looking tagboard script that is written in PHP. It uses mySQL for database, and it is very simple to install and to customize. If you know just a little bit about CSS, then it will be simple for you to modify the looks of your tagboard to match the layout perfectly. The tagboard is valid XHTML 1.0 Transitional, so it loads fast in all browsers. It comes with an online admin panel, so you can delete and edit any tag anytime.

Hosting Requirements: PHP
Database: MySQL
Price: Free

   VNETShoutBox  

VNETShoutBox is very customizable, uses css for it's template engine, secure Admin area, ip ban options, swear filter options, smilies and much more.

Hosting Requirements: Linux, Windows; Apache, IIS
Database: MySQL
Price: Free (GPL)

   TagBoard  

A Tagboard is a very unique and creative script. It is a cool and unique way of allowing visitors to your site to chat, leave messages for you or others, and voice opinions. It adds that extra touch of interactivity to your site, which will make it that much better!

Hosting Requirements: Apache 1.3+; PHP 4.1+
Database: MySQL 3.23+
Price: $9.95

   Flash Chat Zone  

This product is great for any website where the visitors need to communicate fast to each other or to the website staff (live support system). It's very easy to install and to integrate on all websites. It uses flash to optimize server load and offers to your clients a better interface than other chat systems. Does not require any registration from your visitors. It's fast and very efficient!

Price: $25

   FlashChat  

FlashChat is a very simple chat room that anyone can add to their website. It includes support for multiple chat forums. It is very easy to set up and only requires that you create a couple of tables in MySQL and change a few variables in the PHP script to match your server. FlashChat is nearly 100% customizable. All of the colors and fonts are set in a single configuration file

Hosting Requirements: PHP 4.1+
Database: MySQL
Price: $5

   Moiat Chat  

Realtime chat script. Supports unlimited number of rooms and smiley icons. There is a banning system to keep the unwanted people away. Has full cyrillic support. The needed information is sotred in text files, so no MySQL or any other database is required to run the chat script. The script is easy to setup and configure. Ot has simple and light, good-looking design.

Hosting Requirements: Linux, Unix, Windows; PHP 4
Price: $50