In this thesis, we present a model that aims to support business activities conducted through a network of collaborations that generates value in different, mutually beneficial, ways for the participating organisations. Particularly, we propose a practical model for the theoretical representation of Digital Ecosystems, which supports four properties of `Interaction', `Balance', `Loose Coupling' and `Self-organisation'. The interaction model in this distributed environment should satisfy the long-running nature of business activities in a loosely coupled manner. The proposed model for distributed transactions focuses on the dependencies that arise due to the sharing of data within a transaction or the release of partial results and shows how these can be handled using a flexible lock scheme and using an extended log mechanism. The conceptual agent-based design presents a distributed coordination model which handles long-term business transactions. The temporary virtual networks formed by long-term business transactions that involve the execution of multiple services from different providers are used as the building blocks for an underlying scale-free business network. It is shown how these local interactions, which are not governed by a single organisation, give rise to a fully distributed networked architecture that reflects the dynamics of businessp rocessesin a loosely coupled manner when it respectsl ocal autonomy. An optimised recovery mechanism not only provides a forward recovery method for avoiding the (costly) full recovery procedure, but also is isolated from knowledge of the local state of participants and so respects their local autonomy. In order to provide a sustainable environment with high connectivity between participants of a digital ecosystem, the architectural design is based on dynamically formed permanent clusters of nodes; the so-called Virtual Super Peers (VSPs). This results in a topology that is highly resilient to failures. These failures can be categorised from purely transactional breakdowns to physical network disconnections. The self-recovery method is designed using time-out locks, which can save the consistency of the interaction model, and high connectivity and the self-organising method of creating Virtual Super Peers maintains the stability of the environment. Furthermore, the proposed architecture is capable of reconfiguring itself to adapt to the usage that is being made of it and respond to global failures of conceptual hubs or coordinators. This fosters an environment where business communities can evolve to meet emerging business opportunities and achieve sustainable growth within a digital ecosystem.