This report outlines the development and implementation of the collection of resources designed to support institutional publishers and service providers (IPSPs) in assessing to what extent they are financially sustainable, and provides them with tools and intelligence to help them become more so in the future, a deliverable of DIAMAS Task 5.5. It includes a description of the process that led to the writing of the new resources, their review and online technical development as part of the European Diamond Capacity Hub (EDCH). It also refers to the feedback and revisions process, and provides considerations about future sustainability and development as well as plans for engagement and dissemination. We define the toolsuite of sustainability resources as a set of tools and resources, such as case studies, templates, reports and recommended readings that IPSPs and funders, sponsors and donors (FSDs) can use to both advocate for, and to support the practical implementation of, Diamond Open Access (OA). The suite of sustainability resources includes new assets for a variety of stakeholders, including IPSPs and funders, sponsors and donors (FSDs), as well as links to self-assessment tools developed as part of the DIAMAS project, and other resources. The resources are grouped into four sections: Advocacy Resources; Tools; Research; the evidence base; and Further reading. The toolsuite of sustainability resources launched in January 2025 and can be accessed at https://toolsuite.diamas.org/toolsuite-sustainability. Related works https://zenodo.org/records/14727743 https://zenodo.org/records/14626445 https://zenodo.org/records/14904444 https://zenodo.org/records/14898558 https://zenodo.org/records/14621236 https://zenodo.org/records/14621767 https://zenodo.org/records/13833718 https://zenodo.org/records/14626659 https://zenodo.org/records/10907086 https://zenodo.org/records/11383941

This deliverable is currently under review by the European Commission.