In the new emerging communications infrastructures there is the desire and the demand to build applications with every increasing requirements in what concerns real-time and dependability. However, the dynamic characteristics of those environments make it difficult, if even possible, to always offer the desired quality-of-service (QoS). It is thus important to have some support to handle QoS in such scenarios. In this paper, based on the quasi-synchronous approach, we propose a set of group communication protocols with different QoS properties (timeliness, order, agreement), that are built in a component based fashion. Depending on the characteristics of the environment, applications may choose the best QoS that is still possible to have at a give moment.