Along with the introduction of OS X Mountain Lion, Apple released a public beta of Messages for the Mac on Thursday. Messages will replace iChat when Mountain Lion ships this summer and supports several instant messaging services.
Apple releases public beta of Messages for the Mac
Messages for the Mac supports AIM, Jabber, Yahoo! Messenger and Google Talk, messaging with iPhone, iPad and iPod touch users, and removes SMS message cap concerns since it sidesteps cell carrier plans.
Just as it does on the iPhone, Messages on the Mac can link to your phone number and Apple ID, and it syncs conversations between devices.
The Messages public beta is available as a free download at the Apple website.