Freek Van der Herten has a new post to his site sharing a resource you can use to more easily keep up with PHP internals and RFCs - the externals.io service.
When features get added to PHP there’s a lot of discussion first about the new functionality. This is done on the so-called internals mailing list. You can try to follow the discussions via a rather ugly interface at http://news.php.net. The site looks like a very old school web email client where all conversations are just running through each other.
A couple of days ago Matthieu Napoli launched his new site externals.io. This site makes following internals a lot easier.
The externals.io site provides a clean interface to the discussions happening on the php.internals list, including nested threads and the ability to track unread messages. It definitely makes it simpler to keep track of the line of emails in a thread, but it's definitely read-only with no intent on being a full on mailing list replacement.