24 days in december is a site where every day, from start of December until Christmas, a new post by someone in the wide PHP community is published. The blog authors are hand picked by Andreas Heigl who runs the site. Here's an excerpt of the post by Kalle Sommer Nielsen that was published to today.

PHP has a tremendous community behind it, that community consists of you and me, and millions of others that help promote PHP by continuing to develop awesome applications that power some of the biggest websites in the world, but within this community exists a relatively small community that actively develops PHP, such as making it run on your favorite platform or making your favorite extensions compile and work or even keeps the documentation up-to-date. Today I want to dwell into that community, and perhaps giving you flavor enough to contribute back to PHP with code

https://24daysindecember.net/2017/12/11/giving-back-to-php/

Be sure to check out the posts by Morten Bergset, James Titcumb, Juliette Reinders Folmer and all others too.