The 6th International Workshop on Massively Multiuser Virtual Environments a forum for researchers and practitioners working in the field of massively multiuser virtual environment, and will encourage discussions based on the presented papers to identify current and future research topics. The workshop is particularly interested in raising discussions about the following questions: (i) How is MMVE technology developed for games reused for distributed virtual environment in other domains, such as training? (ii) How do the life-cycles and payment models of games integrated into social networking systems (Facebook etc) influence game development? (iii) How can MMVE technology leverage parallel computing technology, including multi-core (Cell, GPU), tight clustering (transactional memory, distributed shared memory) and distributed systems (P2P, Clouds)? MMVE will call for papers of up to 6 pages with a deadline in October 2013.