Download Here Facebook App FB Chat Messenger for Windows Desktop

Eventhough Facebook chat messenger isn't something new for you, it means that you still could access them with Non-Facebook chat app such as Yahoo messenger, Live Messenger, Adium, and more that support with Facebook chat intergration, but with this launching it is indicated that Facebook really serious to give totally best services for the users.
With this new chat app messeger, it's allowing you to access your Facebook account to chat with your friends without you have to login to www.facebook.com, which it's said by Facebook on Facebook Help Center:

You can chat and messege your friends on Facebook
You are enable to see the latest updated from your friends in ticker
You still can see the notification about what's going on

You can just simply download Facebook FB chat messenger app for you Windows below.