Digital ecosystems transcend the traditional, rigorously defined, collaborative environments from centralised, distributed or hybird models into an open, flexible, domain cluster, demand-driven, interactive environment. A digital ecosystem is a new-networked architecture and collaborative environment that addresses the weakness of client-server, peer-to-peer, grid and web services. In this keynote, we will provide a detailed explanation of digital ecosystems,their analogy to ecological systems, their scientific innovation, technical exploration including architecture, swarm intelligence, design and implementation, their comparison to existing networked architecture, social, cultural and economic impact the networked economy. We will also provide several practical examples as well as demonstration of swarm intelligence-based self-organised digital ecosystems. Keywords: Digital ecosystems, digital ecosystems architecture, swarm intelligence, self-organisation, self-empowerment, self-coordination, self-defence.