Whatsapp

Send and receive messages while on the computer and not just a mobile device

Download Whatsapp free

Skype

Send and receive text and video messages

Download Skype (OS X 10.9+) 7.8.388 free

Viber

Chat with one or more people with messages synced to other devices

Download Viber 3.1.0 free

Skype

Enjoy the classic user interface of a popular video and audio calling program

Download Skype 8.16.0.4 free

Messenger for Desktop

View and send messages on the desktop page

Download Messenger for Desktop 1.2.4. free

LINE

A powerful communications suite for staying in touch with friends and family members

Download LINE 3.4.1 free

FaceTime

Video chat with friends and family members at the touch of a button

Download FaceTime for Mac 1.0.5 free

Facebook 4 Mac

Social media site with no installation and that is separate from the browser

Download Facebook 4 Mac 4.0 free

Telegram for Desktop

Send and receive messages and notifications from any device

Download Telegram for Desktop 1.1.18 free

Messages

Enjoy an integrated messaging platform designed for Mac with integrations for other popular programs

Download Messages Beta Beta 8.0 free