Based on the background and examples summarised above, a VRE can be considered as a set of applications, services and resources integrated by a standards-based, service-oriented framework which will be populated by the research and IT communities working in partnership. The scope of the components needed to build this framework is further discussed with examples in Section 5.
Multiple domain-specific or community-specific gateways to the VRE will exist, in parallel serving the needs of different communities but achieving maximum synergy and cost-effectiveness by being based on a common framework which enables reuse of generic open-source components, referred to as services. The example of portals given above is just one example; lightweight programming libraries is another, permitting integration into ``heritage'' codes.
It is not the intention of JISC's VRE programme to produce a complete VRE, but rather to define and help to develop the common framework and its associated standards and to encourage others to work within this framework to develop and populate VREs with applications, services and resources appropriate to their needs. The intention is to maximise the value and benefit of future investment in this area by both JISC and the Research Councils, to secure community contributions and to promote sustainability.
VREs must cater for a wide range of scale and complexity of research activities, from small research collaborations with a few partners to large teams with many partners in many institutions. Examples of the latter include projects within the current e-science programme. A balance must be achieved between meeting the needs of specific disciplines and developing capabilities of widespread utility. The wide variety of research activities means that a judgement must be made in each case on the appropriateness of including specific capabilities for the application in question.
In the long run, VREs will have to become self-sustaining within their user communities and service providers. They will therefore have to be seen to provide sufficient additional benefit to motivate this effort. Whilst VREs, gateways and resources will "belong" to their user communities and will respond to and track these communities' evolving requirements, it is expected that there will be mutual benefit in coordinating these separate VRE activities through a common framework with re-useable services and associated standards. JISC, in its closer relationship with the Research Councils, may continue to provide a suitable common reference point for this coordination. There is potentially a role for the Open Middleware Infrastructure Institute (OMII) in providing ongoing support for VRE middleware.
It is important that the VRE development activity has strong links with other related activities such as JISC's VLE and MLE programmes, the research programmes and communities supported by the individual Research Councils, and international developments such as Sakai in the US. It will have many components and services in common with these.