The VHL increases progressively the interoperability, understood as the integration and communication between sources and information flows, both among its instances as among these and others associated networks. Thus, the set of methodologies and applications of information sources of VHL (see Methodologies of Information sources of VHL) is developed in accordance with this premise.

The interoperability between sources and information flows is crucial for the convergence of data and contents produced and operated by geographic and thematic instances of VHL in a decentralized manner in a single an only network. The interoperability is therefore, a strategic guideline for the sustainability of the operational framework in the networking of the VHL (see The VHL as network operational framework).

Following this conceptual model, VHL integrates and interoperates methodologies and technologies, through information systems collaboratively. The systems are arranged in layers, or levels of processing, schematized as follow:

Data level – it contains the files or databases with records of the contents. The data files are accessible based on protocols of free access, which allows its indexing by search mechanism or indexers.

Index level – it contains the index files for retrieval of data, arranged in the systems or databases. Different indexers applied to the same data files represent this layer.

Interface level – set of different interfaces, mostly Web pages, but also including mobile telephones, digital TV, among others, accessing the indexes for retrieval and navigation in the contents. The interfaces are, therefore, unlimited numerically and in presentation formats. What characterizes this organization in layer is the independence between the three levels, making possible the operation of the systems and information sources of VHL in different servers, computer systems, application of designs and conception of different interfaces, etc. This organization defined as architecture based in service, parcel up the contents of the VHL and offers different products and information services.

Besides expanding the visibility and accessibility of content network, the progressive adoption of the architecture based in services in the development of VHL and its associated networks is priority for the consolidation of social networks of learning and informed environments, because it gives instruments to network with interoperable, scalable and interactive tools

VHL and the networks which are associated (see Associated networks) use open protocols of interoperability and collaborative tools that promote the interaction of social network, such as RSS, OAI, wiki pages, blogs, forums, chats, feedback of users and ranking of documents, personalized services based on profile of preferences, social bookmarking, folksonomy, mashup applications, and others.

The expression of social networks on the Internet has been related to the term Web 2.0, associated with the concept of using of the technologies in promotion sharing of information and knowledge and collaboration between users. This term, however, does not represent an update to Web technical specifications, but a new way to use its potentialities both for end users as for developers of applications.

In this sense, VHL is state-of-the-art in this trend and meets these new demands. The perspective of VHL to the Web is understood as a platform based on services provided by different applications, originated in different spaces and produced by different institutions. In line with this approach, the software, for example, is no longer seen as a product, but as a service.

The Use of interoperability standards is inexorable to the development of applications organized according to the architecture based in services, since these developments are built from local Web services that are distributed and used by all network.

The conceptual, analytical and implementation models of the Web services, and consequently the architecture based in services, has as example a searching service in any database. In the conceptual model, this Web service can be originated from an application that will retrieve a list of results according to the search executed. At the same time, this application can be integrated into a portal to make available to provide for users the list of corresponding search results. It’s about, respectively, web services, widgets and portals.

According to this conceptual model and analyzing the possibilities of using a Web search service, the service can be used or reused in different ways, for example, for a free or advanced search. Thus, a free search service can be performed by an application responsible by the availability of a search box and this, in turn, integrated into different portals. The same applies to the service of advanced search and a formulary of advanced search integrated into a portal.

Whereas both of the conceptual and analytical models can be implemented, for example, in the collections of the SciELO network, it is possible to develop a set of Web services available on each of the instances SciELO and from these, develop various applications, involving those services. The applications can be used in the development of new portals or integrate into existing portals to make available to provide new information services to users.

The explanation and application of these models in architecture based on service the context of VHL and its associated network, promote the interoperability of the network of information sources network through the availability in open access of repositories/directories of Web services and applications (widgets), which can be invoked or reused by other applications and developers involved in these networks.

The platforms of personalized services, with its feature of unique identification of the user, work like as a passport that is valid for all instances of the networks VHL and SciELO. The record, as well as the use of personalized services, is free. The passport and a management of the personalized services will be valid in the future for the networks CVSP, ePORTUGUÊSe and others associated networks.

The expectation is that the number and type of services offered will increase progressively in the future, as the share of documents from my collection and my interest profiles; the functionality of Single Sign-On, which will enable the automatic recognition of the user in both networks, with only one login in any of the networks, among others.

The need for interoperation among the applications and information systems is facilitated progressively by increasing the portability, reuse, creation of components with low dependency between them and the use of pattern. The incorporation of these mechanisms through VHL establishes a new governance of Web services, resulting in the use of this model by its associated networks.