The short explanation is: use Chatter in Apex. Many Chatter REST API resource actions are exposed as static methods on Apex classes in the ConnectApi namespace. These classes are called “Chatter in Apex.”
In Apex, you can access some Chatter data using SOQL queries and objects. However, Chatter in Apex classes expose Chatter data in a much simpler way because data is structured for display and localized. For example, instead of making many calls to access and assemble a feed, you can make a single call.
Watch the Chatter in Apex Video Tutorial
The team working on Chatter in Apex has created a video that walks you through creating an Apex controller, a Visualforce component, and a Visualforce page that displays two Chatter feeds side by side. It’s a very simple example to get you up and running as quickly as possible.
Do the Chatter in Apex Quick Start
The Quick Start in the Apex Developer’s Guide also builds a page with side by side Chatter feeds. The difference between the quick start and the video tutorial is that the quick start displays feeds from Chatter groups while the video displays the news feeds from Salesforce Communities.
Here’s a screenshot of the Chatter Groups page you’ll create in the Quick Start:
Use Chatter in Apex to Build Custom UI in Salesforce
If you want to create a custom Chatter experience in Salesforce, check the Chatter in Apex documentation—the functionality you’re looking for exists and is awesome!