Top rated in Instant Messaging & VoIP

Send instant messages, share files, and hold video conferences.

Do more than just IM with Yahoo!

Popular and, probably, the best instant messaging client for you Mac.

Send messages, have group chats, and share pictures using the Whatsapp services.

A chat-based workspace in Office 365 with private group conversations.

Video chat/calling tool; see up to 6 friends at once.

VoIP program which allows you to make phone calls over the internet.

Send messages, make video calls and stay connected with your friends.

Send messages, exchange files, and make voice and video calls.

A desktop messenger that allows using the services of Telegram.

Free-to-use voice and text chat application for gamers.

Powerful and efficient instant messaging client.

iGlasses allows you to adjust and manipulate your webcam's video settings.

QQ connects you to over 600 million Chinese QQ members and many of your favorite websites and useful tools.

Google, Skype, Yahoo, MSN, AIM, Jabber, Facebook, SMS, Fax...

Supports private and group communication as well as file exchanges.

Integrated functionality for instant messaging, presence, conferencing and voice.

Communicate with all of your friends personally and in group chats on your Mac just as you would with your mobile device.

Stay in touch with your colleagues and monitor conversations.

Freeware Mac OS X IRC client created by Steve Green.

Spark is an open source, cross-platform instant messaging client for businesses.

Traditionally, chat clients on the Mac have been anything but glamorous.

Chat application that tries to integrate most of the major chat networks into one application.

Seek out friends and colleagues on the Internet with the latest version of this megapopular chat pro