This document describes the ePLANET Collaborative Working Environment (CWE). The CWE have dif-ferent tools to be used for project members and envelops the project and consortium information, internal communications, meeting minutes, encompassing a wide set of features in order to manage documentation repository, internal communication, planning, including milestones and tasks sched-uling, Issues tracking, and progress Reports management. The deliverable covers the ePLANET Collaborative Working Environment (CWE), and its maintenance throughout the project, which is based on three main tools: Nextcloud for file sharing and other utilities, Notion used as a Wiki for meeting minutes, tracking and verification of objectives, and GoToMeeting for online meetings. The D1.1 Collaborative Working Environment (CWE) is the first deliverable of the project and WP1 with the aim to be a practical guide to the CWE of ePLANET, for present and future project members. This deliverable is a public document addressed to the project members and to the European Commission’s Project Officer.