Today's virtual environments are expected to be distributed to allow collaboration for common purposes. However, they must ensure a high level of Quality of Service (QoS) to the user, especially in an open context with unknown, a priori, man-in-the-loop event occurrence. This paper presents our Distributed Virtual Environment COllaboration Model (DVECOM) and its implementation, which aims to provide an end-user QoS support for, distributed virtual reality applications.The idea of DVECOM is to guarantee full consistency and soft synchronization of the virtual world distributed displays, with the least rendering degradation possible, and also to auto-adapt the rendering in accordance with the retained strategy, ensuring best effort and least suffering for virtual world rendering.This representation degradation is driven by the users' choices. The receiver-side protocol is based upon the end-user preferences, physical level capability information, as well as the pertinence of the notification to each client (contextual end-user information). When available, such guarantees would make it possible to use DVE out of a closed, oversized, very restricted context for industrial collaborative applications with an expected QoS.