LanTalk XP can be run on local networks to provide messaging functionality. The program stays in the background and displays an icon in the system tray, until you or one of your co-workers decides to use it. The interface is very similar to Winpopup, the user only being able to see one message at a time. It’s true that shortcut keys can be used, but this, in my opinion, is not a very efficient way of exchanging information. 
The program is compatible with the “net send” Windows command, and with the Messenger service. You can send messages to any computer in your LAN that has the Messenger service enabled. However, if you try to start LanTalk XP on a computer with the Messenger service already started, you’ll get an error.
You can configure the program to act just the way you want. Several useful features are available among which I’d like to mention the auto-answer function, the fast replys capability, the word and computer filter and the possibility to play a sound whenever you receive a message.