eXo Chat application has two installation modes available:
The embedded mode: eXo Chat is deployed inside eXo Platform.
The standalone mode: eXo Chat is installed into a dedicated server.
Each mode has its advantages:
The embedded mode is simplier architecture, you have not to install an another Tomcat server.
The standalone mode has better scalability and performance since server resources are not shared between eXo Platform and eXo Chat, and since the eXo Chat can be clustered.
More details about the installation procedure through these two parts: