Communication

Free

iMessage lets you send messages to anyone on a Mac, or an iPhone, iPad...

Free

Do more than just IM with Yahoo!

Free

Stay connected to Twitter directly from your desktop.

Free

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

Free

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

Free

Strong desktop email client with superior speed and responsiveness time.

Free

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

Free

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

Free

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

Free

It helps you build custom Twitter timelines on your Mac.

Free

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

Free

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

Free

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

Free

Stay in touch with your colleagues and monitor conversations.

Free

Powerful and efficient instant messaging client.

Free

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

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

Free

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

Free

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

Please, before posting useless comments check the user's guide or support...

Free

Supports private and group communication as well as file exchanges.

This application lets you check your Facebook profile from your Menu Bar.

Free

A program for checking your Gmail account from your desktop.

Free

Enjoy the advantages of using Gmail fully separate from your browser.