Check out the latest version of FontAwesome.
Version 5 has been re-written and re-designed completely from scratch.
One part of the rewrite is that brand icons have been organized into their
own collection. Whether you are using the full suite or just the brands
bundle, you'll be referencing these icons with the fab class name.
<i class="fab fa-react" />This will give you a React icon.
Check out all the different brand icons here.