Peer-to-Peer (P2P) networks have been around for some time now, and are often used for file sharing applications over the internet. In a P2P topology, every computer connected to the network can be a peer, and no central server is required. This makes P2P networks very flexible, scalable, and reliable as there is no single point of failure. These capabilities also make P2P networks very suitable for the GeoWeb, as their architecture easily allows sharing and synchronization of heterogeneous, distributed, geospatial data over the Web.

All peers are equally capable of providing and consuming resources, and they can advertise resources that they want to share to other peers that maybe interested in sharing them. Given the dynamic structure of the GeoWeb, where new geospatially-related data appear rapidly and in ever growing quantities, this is the only architecture that can handle these proliferating environments. This has already been proven in other application domains, such as the use of Voice-over-Internet protocol (VoIP) technologies like Skype for tele-communications.

But a Peer-to-Peer structure alone is not sufficient for a pervasive, dynamically-changing GeoWeb. The architectural infrastructure of Event Driven (ED) capabilities are also needed, for enabling the automation of data sharing and replication as well as for handling notifications about changes and their metadata. An ED architecture is particularly necessary in collaboration environments, such as in crisis management, that require realtime data exchange to gain a common operating picture.

SOAP-based web services, as well as RESTful architectures, are still following a client/server paradigm as they expect a specific functionality to be returned by a request even if the request response is asynchronous. This impedes agility, as the consumer and the provider of the functionality are depending on each other. Both architectures allow a decoupling of the message or interface level from the implementation, but not from the functionality. Even in an orchestrated controller environment, such as a BPEL-driven service component architecture, the controller needs to know which functions to call to get an expected result.

In contrast, in a ED/P2P architecture, the functionality of distributed system components is totally decoupled. The component that creates an event does not need to know what a subscriber to this event will do with it, or even whether any component is interested in the event at all, and the publisher of an event does not direct any event directly to a consumer component. The subscriber to an event relies only on the information published, and is unaware of where and by whom the event was created. The subscriber may change the functionality that is driven by this event at any time, without the event producer having any knowledge of such a change.

Paired with the scalability and flexibility of the P2P network, the GeoWeb becomes a dynamic horizontally- and vertically-scalable infrastructure that can support and integrate many application domains, especially geospatial applications that are driven by realtime information, such as in Aeronautical Information Management. In such an event-driven architecture, the more rigid orchestration component of a web services architecture using SOAP or REST is replaced by a Publication/Subscription framework that is totally decoupled and autonomous. This fulfills the general notion of the Web as having no centralized administration point or authority that drives the overall functionality that is available anywhere to its users.