1 Introduction

How to help the users find their way through the jungle of information services is a question which has been raised since the early development of the WWW (see e.g., Egret [1994]), when it became clear that a big centralized system was not the efficient way to go.

Obviously the World Wide Web is a very powerful medium for the development of distributed resources: on the one hand the WWW provides a common medium for all information providers - the language is flexible enough so that it does not bring unbearable constraints on existing databases - on the other hand the distributed hypertextual approach opens the way to navigation and links between services (provided a minimum of coordination can be achieved). Let us note that it has been already widely demonstrated that coordinating spirit is not out of reach in a small community such as astronomy, largely sheltered from commercial influence.

Searching for a resource (either already visited, or unknown but expected), or browsing lists of existing services in order to discover new tools of interest implies a need for query strategies that cannot generally be managed at the level of a single data provider.

There is a need for road-guides pointing to the most useful resources, or to compilations or databases where information can be found about these resources. Such guides have been made in the past, and are of very practical help for the novice as well as the trained user, for example: Andernach et al. ([1994]), Egret & Heck ([1995]), Egret & Albrecht ([1995]), Heck ([1997]), Grothkopf ([1995]), Andernach ([1999]).

In the present paper our aim is to address the questions related to the collection, integration and interfacing of the wealth of astronomical Internet resources, and also to describe some strategies that have to be developed for building cooperative tools which will be essential in the research environment of the decade to come.