The Internet is broken – and we are using it to access and distribute all of human knowledge. Data monopolies hold and enclose upon personal & public datasets, threatening universal access. To tackle this problem, between 2013 and 2015 we performed a series of design & development sprints in collaboration with researchers, librarians, and civic technologists working to preserve the digital knowledge commons. Out of this research we built Dat, a distributed ledger & peer-to-peer data sharing toolkit.