Open Source Delayed – pay for early access?

Sentry funded a history of open-source delayed, finding it more common than expected.

Between fully-open (MIT) and viral/copy-left, is there an open-source license that can sustain developers as well as users?

Historically, small companies with big customers who wanted the security of having the source if their small nimble supplier fails would have conditional or partial open-source (e.g., Sun's SCSL).

To date, the only open-source business models seem to be support, SAAS deployments, and value-add's (premium or custom). But given the strategic value of being first in technology, perhaps OS software could also be sold under the early-access model of publishing subscriptions.

(No endorsement of Sentry implied.)