Due to the affordability and high quality of the emerging XR devices and platforms, immersive media content has become more accessible to a wide variety of consumers while their technology gains increased interest from content creators. However, the previously mentioned technological advancements are focused more on sensor or rendering-display technologies, while the development of software tools that assist professionals, indies or hobbyists to create immersive content and narratives is left behind. In this work we introduce XR360, a unified toolkit for producing 360° immersive experiences by embedding 3D captured human performances in 360° captured scenes. The presented toolkit comprises a complete solution for content acquisition, 3D asset creation and 3D-360° fusion. It combines a volumetric capturing studio, a performance capture production tool and a 360° fusion application, designed to operate in a cascaded, but disjoint, manner while remaining user-friendly by hiding complex technicalities from its end-users.