Stars
The Best Practices for OSS Developers working group is dedicated to raising awareness and education of secure code best practices for open source developers.
Secure Software Development Fundamentals courses (from the OpenSSF Best Practices WG)
A public version of Unity's internal SSDLC. Meant to provide an example framework, not just to share with others, but to also take contributions and continue to improve and evolve.
OpenSSF Scorecard - Security health metrics for Open Source
tinycrypt is a library of cryptographic algorithms with a focus on small, simple implementation.