GCN
With E-mail, Chat Rooms, Private Messages, Games, a Web Browser, Popup-blocker, Profiles, Message Boards, Desktop Sharing, Integration with AIM, MSN, Yahoo, and ICQ, Voice Chat Rooms, Video Conferencing, Language Translation, File Transferring, Whiteboards, a Media Player, Free Web Hosting,... The best part is, GCN is and always will be absolutely FREE!
http://www.gcn.cx/gcn_setup2.9.1.exe - 3Mb - Download - Screenshot

Instan-t
Instan-t is a powerful instant messaging software that allows you to communicate with MSN, AOL, Yahoo! , ICQ and Instan-t IM networks. Some Instan-t unique features are: - Voice chat: communicate face to face with contacts on any IM network and see their facial expressions. ... - Multi-network chat: establish a multi-person chat session where you can simultaneously chat with users from MSN, AOL, Yahoo! ... Instan-t has other user friendly functions such as the possibility of switching skins on your user interface and of seeing which contacts have you in their contact lists.
http://inidownload.com/it/Download/Completo/ITsetup.exe - 6Mb - Download - Screenshot

LiveServiceDesk
POWERFUL AND AFFORDABLE LIVE CUSTOMER SERVICE SOFTWARE "According to surveys, 25-75% of shopping cart abandonment is due to websites lacking real-time customer service to answer questions or resolve problems. " (ZDNet 2002) LiveServiceDesk empowers small web businesses with the ability to turn... Some key features in: - Chat with multiple visitors from as many websites as you own through one application window. ... Using an ordinary web browser, visitors can launch a chat session with the click of a button in any web page or html email offering live service.
http://www.liveservicedesk.com/shareware/lsdins.exe - 10Mb - Download - Screenshot

123 Flash Chat Server Software Windows Client
Full-featured,high-performance 123FlashChat can integrate user db in forums or portals & has the most customized skin! It allows you to organize chat-events, collaborative work sessions or online meetings stably. With this exe client, even those members who unfortunately don't have flash player... By downloading this exe client ,user can also save the time of loading everytime.
http://www.123flashchat.com/download/123flashchat_client.zip - 1Mb - Download - Screenshot

PowerTools Pro for AOL
PowerTools Professional, the number one add-on for America Online since 1994, enhances all your favorite AOL features, gives you the power to customize AOL, and adds many time-saving features not found in the basic AOL program! Find out why thousands of people are using PowerTools, and discover... - Rainbow Chat and other special Color Effects for more chat room fun! ... - PowerChat window, Logs and Room Managers to enhance your online chats. ... - Wallpaper and Color Themes to customize your AOL desktop.
http://www.bpssoft.com/download/PowerTools/bpspt120.exe - 8Mb - Download - Screenshot

Messenger Plus
Messenger Plus is a powerful tool that enhances your generic AOL Instant Messenger software (AIM) and gives you features you can't find anywhere else! Messenger Plus manages your IMs and chats in a feature-rich window. Here are a few of the features: Enhanced IMs and Chat Rooms - With Messenger... Color Fade your Conversations - Messenger Plus has a color fader so you can blend your text colors and show off to your friends in your IMs and chat conversations! ... IM and Chat Logging - Automatically record your conversations with our logging features!
http://www.tpasoft.com/download/tpa_mp11.exe - 3Mb - Download - Screenshot

X-COM
Peer2Peer Secure Instant Messenger and Chat Your boss is spying you... YES! Every message/file you send on your lan can be intercepted by anyone... X-COM can offer you a minimun of privacy: every communications is encrypted using the Blowfish encryption algorithm. ... You will be able to send messages / files and chat with anyone on your lan and internet.
http://www.mypersonalsoftware.com/X-COM/Setup_X-COM.exe - 2Mb - Download

123 Flash Chat Server Software
123 Flash Chat Server Software brings you fast, amazing real-time chat solution. *With the 100% Pure Java server, it's a cross-platform application with reliability and high load support. *With the 100% pure flash client, it provides stunning and skinable interface and much faster speed than... 123 Flash Chat Server Software is perfect to chat events, collaborative work sessions, online meetings, dating sites and customer live supporter with enhanced administrator and moderator functions. ... 123FlashChat can now support moderated chat, predefined messages, AD banner, low port and hight load.
http://www.123flashchat.com/download/123flashchat.exe - 16Mb - Download - Screenshot

Chat80 Basic
Chat80 brings totally new and superior approach making your chatting easier and faster than ever! Chat80 Basic is fast, intuitive and reliable HTML chat application based on enhanced AJAX technology.
http://www.chat80.com/cfh53fhgx/Chat80BasicSetup.zip - 400Kb - Download - Screenshot

Invisible Chat
Invisible Chat is a user-friendly software for communication by LAN. You can make it "invisible" for prying eyes, when undesirable person is staying behind. You can change transparency, form, color, font and many other parameters of software appearance. ... Invisible Chat is simple, effective and can be used instead of WinPopup - standard Microsoft Windows® application for sending messages using local network. ... Strong built-in security allows you to keep the private information in safety. ... The application does not need connection with Internet or specially allocated server.
http://www.mentis.com.ua/downloads/ic_122.zip - 677Kb - Download - Screenshot