CASTER Free lets you capture your desktop audio and stream it to any streaming software while monitoring the audio in your headphones without any additional configuration – and it’s all for free.
In addition, you also get access to the Soundboard track. You can play audio (sound effects, intros, alerts, and more) into your stream alongside your other sources. You can use the built-in sounds we have provided or load your own.
CASTER Free also lets you stream audio from specific programs on your Mac if you don’t want to stream the entire desktop audio. You can do this by adding in an application by clicking the top button found in the middle section.

You also have the option to record all tracks from within CASTER – a free feature as well.
And you can add some AU plug-ins to your tracks for cool processing.