The web has been initiallly conceived as a collaborative environment that allows people to interact with each other, but the first tools made widely available were passive ones. They allowed people to conveniently browse the web and to read pages, but not to write and to publish as easily. Now, active tools are emerging. They help users to simultaneously browse and edit documents and to save them on remote servers. This is a first step towards a more interactive way of working remotely, but a complete collaborative environment needs more.

To be efficient, collaboration requires not only a shared space, which the web is, but also some support. The shared space must be structured, each user must be aware of the activity of others, some direct communication between people should be provided to allow them to discuss their common task, and coordination means should be provided. To build such an environment, many resarch issues have to be addressed.

To explore this challenging field of research, we have followed two complementary directions, in developing two different software packages.

1. Amaya is an active web client. It allows a user not only to create, edit and publish pages on the web, but it also provides a structured approach to documents, which is specially helpful in a collaborative activity.
2. Alliance is an integrated cooperative system. It provides users with a comprehensive collaborative authoring environment where they work on shared documents almost as if they were working on a single private document. In addition, it takes takes each author aware of the current activity of others , in a non intrusive manner.

Both approaches will be compared in the talk and their advantages will be shown in live demonstrations.