Messages is Apple's instant messaging application for OS X. The software was originally called iChat, but Apple changed the name to Messages in 2012 with the release of OS X Mountain Lion. Messages supports Apple's iMessage service, an alternative to SMS and MMS that enables Mac and iOS device users to send text, documents, photos, video and other data to one another. Messages also supports other instant messaging protocols, including AOL Instant Messenger (AIM), Yahoo Messenger, Google Talk, and Jabber. And with OS X Yosemite and iOS 8's new "continuity" integration, your Mac will also be able to see and respond to SMS and MMS messages when paired with your iPhone.