At present there are no digital social platforms that are open, distributed and self-managed. The openness enables end-users to customize their interactions through their selection of relationships and applications; and application developers to customize an interface for end-users with existing or new services. The distributed architecture ensures the scalability of content and entities, and the resilience to abuse. The self-managed platform provides the entity with control over its relationships; applications with control over the services it provides; and end-users with control over their interactions. These requirements led to the design of the social platform framework described in this paper. The key features of the framework are its modular design, use of open standards, distributed architecture, and policy-based management.