wordpress-seo by Yoast

Site Kit is a one-stop solution for WordPress users to use everything Google has to offer to make them successful on the web. Maintained by google on GitHub, where it has earned 1,393 stars from the community.

Podlove Podcast Publisher for WordPress. Maintained by podlove on GitHub, where it has earned 309 stars from the community.

LimeSurvey – A powerful, open-source survey platform. A free alternative to SurveyMonkey, Typeform, Qualtrics, and Google Forms, making it simple to create online surveys and forms with unmatched flexibility. Maintained by LimeSurvey on GitHub, where it has earned 3,708 stars from the community.