The emergence of large scale distributed computing paradigms, such as Cloud Computing and Mobile Computing Systems, has opened up many opportunities for Collaborative Enterpise Systems (CES). Collaboration services are at the core of any Enterprise System, aiming to support collaboration among individuals, inter-teams and intra-teams within an enterprise. While most CES sytems have focused on using groupware systems (shared workspaces, video-conferencing, etc.) to support sharing and collaboration within one administrative domain in a rather fragmented way, the trend is to develop CES systems capable to support CES at large scale integrating multi administrative domains and different organizational and hierarchical structures to increase productivity, business value and innovation. The objective of CES is thus to support efficient collaboration at inter-enterprise level at large scale by addressing mobility features of workforce, heterogeneity of resources, multi-domain nature, availability of resources, system reliability, etc.