Comment by ZenoArrow

Even though this metric favours commercially-funded development, I found it interesting to look through the list, thanks to the author for putting this site together.

I also discovered an promising project I wasn't aware of, which was wp-calypso:

https://github.com/Automattic/wp-calypso/blob/master/README....

It's still too early to say for sure, but it looks like we may be seeing the start of WordPress migrating away from PHP.