Sandbox Accelerator idea

From @TracyRagan in https://github.com/ossf/tac/issues/599#issuecomment-4336838677:

These changes support innovation, which is exactly what we want to encourage. To strengthen their impact, we may want to introduce a pre-Sandbox stage called a Sandbox Accelerator program—a structured, one-year entry phase designed to help early-stage projects reach the current Sandbox maturity level. This Accelerator stage would provide emerging projects with focused support around maintainer development, contributor onboarding, governance readiness, release practices, and early adoption signals, which are areas where many open-source efforts typically struggle.

Projects in the Sandbox Accelerator should be evaluated on a regular cadence throughout the year using lightweight health indicators such as contributor activity, documentation completeness, release consistency, community engagement, and alignment with foundation priorities. The goal would be to ensure projects are intentionally progressing toward Sandbox rather than entering the foundation ecosystem prematurely without sufficient structure.

Once projects graduate into the existing Sandbox level, they should continue to be reviewed periodically to assess sustained growth and ecosystem relevance. In parallel, it may also be worth revisiting the Incubating-level entry criteria to determine whether the current bar is unintentionally slowing advancement. Slight adjustments there could create a clearer progression pipeline:

Sandbox Accelerator → Sandbox → Incubating → Graduated

This would create a more transparent and supportive lifecycle that improves project throughput, strengthens maintainer sustainability, and increases the likelihood that innovative early-stage efforts successfully mature within the foundation ecosystem.

xref: https://github.com/ossf/tac/pull/421, https://github.com/ossf/tac/discussions/606

Start by reading the referenced comment in issue 599, then review xref issue 606 and pull request 421 for the surrounding proposal. Define the Sandbox Accelerator scope, evaluation cadence, progression criteria, and relationship to Sandbox and Incubating; done means the lifecycle proposal has an agreed, actionable specification.