Sustainability of open-source software is a continual challenge in the relatively small world of cultural heritage institutions. The challenge is amplified due to the critical preservation implications tied to institutional commitments; cultural heritage institutions are expected to preserve and provide access to repository-held data into the foreseeable future, and yet our models for shared software governance are relatively immature, and commitments to software sustainability ebb and flow over time. The cultural, financial, and philosophical dimensions of the community surrounding the software play as much, if not more, of a role in a project’s sustainability as the technology itself. With a collective thirty years of experience grappling with these challenges, the speakers will offer varied perspectives on approaches to ensuring the software that supports the long-term preservation and accessibility of our digital heritage will still exist tomorrow. This session will dive deeper into the specific challenges faced by a few open-source repository software communities, outlining what the Islandora, Hydra, and Fedora communities have done to address sustainability in their projects, past and present, and how well these measures have succeeded. Specific tactics for engaging in these projects will be offered as a call to action.