The misconception of virtual worlds as „games‟ has prevented these immersive environments from being treated as legitimate areas of inquiry by the Information Systems community. In this paper we argue that these environments challenge our conceptualisation of technology mediation due to the immersive and co-created nature of the digital environment, and particularly, challenges our understanding of information technology mediated collaborative development activities. Acknowledging the interrelated roles played by both human and non-human actors within virtual worlds, we investigate the construction of intersubjective meaning within three small synchronous collaborative development groups. Our findings highlight the complex roles of mediators within such collaborative activities in immersive environments, and the ways in which such mediation manifests through integrated socio-technical systems that are culturally developed.