Sandstorm abandons "open core" and becomes a community supported project
According to a Sandstorm project blog post (Feb ,2017), Sandstorm have abandoned their "open core" business model, taken down their paywall, and liberated all their code. I think this is a great thing for the project, and for the world.
Sandstorm realised that they couldn't build a commons-based business by selling stuff to "enterprise" (corporations). Even Enspiral are sometimes willing to use proprietary freeware (GITHub, Slack, Google Docs, Trello) rather than self-hosting libre replacements, despite the clash of values involved. Why would profit-centred companies spend money on a (partially) free code service when they can outsourcing their computing to The Stacks, and get a proprietary service gratis? The "open core" business model is the worst of both worlds, and it's not the future of funding free code development.
Sandstorm would be better off looking at paying for dev costs by collecting regular, small contributions for sysadmins running their software, and the end users. There are now a number of libre platforms for managing this, including Gratipay, LiberaPay, OpenCollective, and Salt (a BountrySource service).