The Blue-Cloud project started in 2019, under the H2020 EU's research and innovation funding programme, with the aim of creating a European Open Science Cloud for marine data. This involves federating data and e-infrastructures to provide data products and technologies as open science resources for the wider marine research community. Since 2023, the Horizon Europe Blue-Cloud 2026 follow-up project has been advancing this pilot ecosystem into a Federated European Ecosystem. It delivers FAIR and open data, along with analytical services essential for progressing research on oceans, EU seas, and coastal and inland waters. Building on the foundations of the original Blue-Cloud project, the current technical framework remains open, extensible, and adaptable to the evolving needs of the marine research community.
The Blue-Cloud Virtual Research Environment (VRE) is a federation of computing platforms and analytical services, orchestrating computing and analytical services into integrated and managed applications exploiting federated Blue-Cloud data resources as well as external data resources. The VRE is built on the D4Science [1, 2] infrastructure and the gCube [3] open-source technology. From the end-user point of view, it manifests in the EOSC Blue Cloud2026 gateway (accessible at https://blue-cloud.d4science.org), the access point to the services and Virtual Laboratories available to the Blue-Cloud community.
In the context of the Blue-Cloud-2026 project, the VRE is expanded by bringing together multiple e- infrastructures computing resources and services for supporting the needs of the users with larger capacity and new services and features. This document describes the approaches to enable the federation of these new resources and services into the Blue-Cloud VRE, and reports on the currently federated infrastructures that are actively supporting the VRE: Google Cloud Platform and EGI Cloud Compute at INFN-Bari. The federation is achieved through three primary approaches: deploying JupyterHub on Kubernetes resources, either through managed services or Kubernetes set up on OpenStack by VRE operators, to provide access to single-user interactive applications such as Jupyter and RStudio; deploying Galaxy on Kubernetes to enable seamless execution of workflows; and utilizing the Cloud Computing Platform (CCP), which features a pluggable architecture supporting Docker-swarm and Galaxy as execution platforms, offering flexibility for diverse computational tasks.