Google has updated Hangouts for Chrome with a revamped UI that brings it in line with Hangouts version on Android and iOS. More importantly, the Hangout app now supports Mac OSX.
The Hangouts app on Chrome now features a two column layout. All your contacts/messages are present on the left panel while the ongoing conversation thread is on the right panel. A floating action button lets you open up a new conversation. Similar to Hangouts on Android and iOS, you can open up a pop-out window for individual conversations. The new interface is available now on Windows, Mac, Linux and Chrome OS.
It is advised that users on Windows, Chrome OS, and Linux should disable transparent mode under settings in order to see all of the new changes. Update the Hangouts app for Chrome here.