Third Party Rendering support in Houdini Indie will be available when Houdini 15.5 is released at the end of May 2016. All of the renderers listed here will work within the existing Houdini Indie render limits - 1920x1080 for animation sequences and unlimited for still images. Rendering in Houdini Indie will go directly to the renderer without saving out render description files.Details can be found here.
Houdini Engine Indie works with all of the Houdini Engine plug-ins including Unity, UE4, Autodesk Maya, Cinema 4D and Autodesk 3DS Max. These plug-ins let game devs load Houdini Digital Assets which can be created in Houdini Indie or downloaded from the Unity Asset Store and the Orbolt 3D Smart Asset store. Details can be found here.
Huge release with tons of new features. This brings Houdini to a bigger part of the pipeline while the VFX tools become faster and more efficient at handling big data. Full feature list is here.