...
It is based on the ASF project maturity model at https://community.apache.org/apache-way/apache-project-maturity-model.html
History
The discussion around the NetBeans podling's maturity model assessment was started on 2018/09/20, by the Apache NetBeans mentors:
Suggestion by Bertrand Delacretaz to make sure the PMC roster is realistic:
Related References
https://incubator.apache.org/guides/graduation.html
...