DAOstack is an operating system for a new form of web organization: the DAO. Decentralized Autonomous Organizations have captured the imagination of the best minds in the blockchain space, but despite their promise have yet remained an abstract idea. One key point of failure is the lack of solid framework for decentralized blockchain governance. DAOstack provides a general stack for collective value management on the blockchain, including a friendly JavaScript developer environment and an intuitive user interface. Just as HTTP allows the creation and interoperability of web sites and web applications, the DAO stack enables the creation and interoperability of web companies, collaboration apps and DAOs, as well as the alignment of their interests. The result is a new web of open collaboration, in which collectives can self-organize around shared goals and values, not limited by pure economic growth. We believe this to be a critical step in the evolution of society toward a more cooperative and sustainable future.