Get Cycles

Cycles can be used as a standalone renderer, but it is integrated into applications as well.

Blender

cycles_blender
Cycles is fully integrated into Blender, a 3D Open Source content creation suite. Blender can be downloaded from blender.org.

Poser

Cycles has been integrated into Poser under the name “Superfly”. You can get Poser from smithmicro.com.

Rhino

Integration is in progress and should be available with the upcoming Rhino 6.

Source code

If you want to take a look at Cycles source code or contribute code, please visit developer.blender.org.