There currently exists a fairly well developed awareness that today's organizations are subject to increasingly rapid and significant processes of metamorphosis. The world today is in a transition phase whereby the models underlying business, communication, education, working, and everyday life are changing. Many organizations are no longer strictly hierarchically structured, but go more for vertical integration, networked clusters, project groups, and flattened hierarchies. Dramatic changes in job situations and working conditions are occurring in many areas. In the future, individual and team-based work in organizations will be characterized by a degree of flexibility and dynamics that will go far beyond many of today's developments and examples. On demand and ad-hoc teams, virtual organizations, distributed and mobile workers are only initial examples of organizational innovations to be expected in the future. In the new technology society, there is a need to form alliances; there is a high competition for skilled workers, and this creates a contention between organizations and high level of fluctuation in the workforce. This problem originates from the fact that in some societies, organizations were formed to provide employees with lifetime employment and there was a stable linkage between the employee and their employers. In the new society, workers move frequently from one employer to another and from one company to another. Companies need to form alliances to be able to create new technologies. They are international and work around the globe providing international solutions. The world is becoming "a global village" in the technology sense as well as in the social and working habits. This new behavioural change presents a need for a new organization model as well as a new workplace model. Teams have become an increasingly important part of business success. One of the most exciting new challenges in modern business life is the need to collaborate within teams, which are geographically distributed across the country or the world. Teams will affect our daily activities, our workspaces and will change our social interactions. The creation of so-called virtual teams of members who are geographically dispersed but electronically connected has already set many companies on fire. In spite of all euphoria, team-based organizations are looking for workspaces that enable and support team behaviour and processes. Teams ask for a new range of tools and support, providing more flexibility in adapting dynamically to special needs. Virtual teams face greater obstacles and ask for more flexibility and information technology support than traditional teams do. New paradigms, technologies, information systems and communication infrastructures are required to provide virtual teams with the necessary means in order to strengthen the power of an enterprise. Much more research needs to be done on how to link people and teams by technology to enhance collaboration and increase productivity. On the technological side, we are experiencing the convergence of data, voice, wired, and wireless networks; the convergence of physical and virtual places; convergence of applications and telecommunication services; convergence of the home and the workplace, and others. So, solutions are needed to assist this transition, help the convergence, and allow the migration towards new forms of collaborative work and new tools and technologies, enabling them. The role of information and communication technology in these developments is manifold. On the one hand, it initiates and triggers new forms of communication and cooperation processes. On the other hand, it provides the infrastructure and application software needed to meet the requirements, which result from new ideas on organising work practices. Colleagues, contents as well as contexts, processes and structures will be changing frequently. It is time for these developments to be reflected in the design of equally flexible and dynamic workspaces. Solutions, which exist today, are essentially centred on individual work and on widely isolated tools and services. To support teams, particularly geographically dispersed ones, they have to evolve towards collaboration infrastructures, which are dedicated to teamwork within virtual organizations. This does not call for the development of very new technologies, but for the integration of available technologies and a functional enrichment to support context-oriented collaboration under unified user interfaces, which follow an intuitively comprehensible metaphor. The basic question to be answered is: How will we be able in the future to dynamically construct workspaces with distributed people, resources, real and virtual rooms and customize them for a given task or project? This thesis acknowledges the growing need for collaborative work environments supporting teams working on specific projects, in particular when team members are located at different and, over time, changing places, possibly in different time zones. It is essential that such environments allow team members to switch between different projects, make it easy for them to preserve and restore the work context of any given project, allows them to reserve and tailor physical workspaces as team members move and change places, and last but not least be sufficiently secured. The following three key observations are being taken into account: Different people (and organisations) typically work with different local tools and services, be it for reasons of culture, installed base, or legacy. For them to collaborate, it is necessary to hide the specifics of e.g. communication or presentation tools under a more unified and intuitive user interface, and at the same time provide built-in adaptability to and transcoding between basic services, e.g. to achieve unified messaging. There already exist a number of collaboration tools and group-ware services and more will emerge. The answer of this thesis is to use them as a reservoir of building blocks and to encapsulate them in a particular unified shell so that they can be integrated into the Co-operation Platform for use of higher-level services in terms of a project's application domain. Many physical work places already tend to be non-territorial; team members use them according to room availability. Thus, facility management services need to be made available across networks, to administer physical rooms and their interiors. That makes it possible to remotely reserve physical workspaces, to personalise and restore their equipment and furnishings, to account for usage, to track and locate people and resources. It will be shown, that today's computer-based technology together with efficient communications has the potential for superior solutions that maintain the information base needed by the team and the relations among team members, while overcoming the physical barriers among them. This thesis presents research results on the potentials of Co-operative Workplaces, which are being seen an alternative to traditional, work-sharing organizations, which are not well-suited to reacting dynamically, flexibly, fast and economically enough to constantly changing customer demands. Since after all we as physical beings are dependent on physical rooms to live and work in, a sensible symbiosis of physical and virtual workspaces is being advocated, to make the best use of information and communication technology advancements. The objective is to design and develop a framework for such future workplaces by bringing together information and communication technology, architecture, design and management of buildings, and new flexible forms of individual and joint work. Within the course of this thesis, an architecture together with a prototype serving as a proof of concept for an open, teamwork-oriented, and unified Co-operation Platform will be presented. It focuses on users, their work contexts, and usage scenarios by providing a unified and worldwide accessible platform based on widespread open standards and Internet technologies. The Co-operation Platform and its components have been prototypically implemented in order to support the creation of Co-operative Workplaces, which can be flexibly built, customised and run according to user needs. They bind dynamically, project information, team members, their physical workspaces, and information tools in a context that is pervasive, secure, and transparent.