The disclosure describes a distributed, pluggable architecture for an artificial reality (AR) system that enables concurrent execution and collaborative scene rendering for multiple artificial reality applications. For example, an AR system includes an image capture device configured to capture image data representative of a physical environment. The AR system also includes a head-mounted display (HMD) configured to output artificial reality content. The AR system further includes a plurality of concurrently executing artificial reality client applications. The AR system also includes a concurrent application engine configured to control rendering the artificial reality content as a common scene that include one or more objects from each of the plurality of artificial reality applications.