Yahoo! Messenger is a popular instant messaging client and protocol provided by Yahoo!. Yahoo! Messenger is provided free of charge and can be downloaded and used with a generic 'Yahoo! ID' which also allows access to other Yahoo! services, such as Yahoo! Mail, where users can be automatically notified when they receive new email. Yahoo instant messenger also includes a security feature which allows the user to be 'invisible' to whoever they choose.

Yahoo Messenger for mac Features

• Send text messages in real-time to your friends on Yahoo! Messenger.
• Call friends on their regular or mobile phones from Messenger for as low as 1¢ a minute (Phone Out account required).
• Send text messages from Messenger to your friends mobile phones for free.
• Plug in your webcam to share live video with your friends on Yahoo! Messenger.
• Instant message with many friends at once in a conference room (includes voice capabilities, where available).
• Send files instantly to a friend while you IM (2 GB limit).
• Get notified when new a new Yahoo! Mail message arrives.
• When friends call you on Yahoo! Messenger, they can leave you a voicemail if you're unavailable.
• Express your feelings with these animated, smiling faces.
• Tell your friends what you're doing, seeing or feeling by customizing your online status message.
• IM with a font, color and style that suits your personality.