Consider Hack Lang http://hacklang.org/. Perhaps it’s PHP’s brightest light.
FB has put considerable effort to fork PHP and developer their own language + interpreter for good reason. Change is likely too slow or wouldn’t be made in PHP itself.
What your describing directly points to Hack Lang. Even their syntax is:
<?hh
We should all take a look at Hack Lang (myself included). It could be what PHP 7 will be in a few years but is ready and available to use today. I'm watching this right now as motivation! (OSCON 2014: Include Hack - HHVM - PHP) http://www.youtube.com/watch?v=JrPGa1JDX38
I'm not sure if this was added to the article after your reply, but the author mentions Hack specifically, along with some caveats about it's adoption, namely that it is currently unkown how widespread Hack will be and how you're basically at Facebook's mercy in regards to the future of the language.
As for adoption, the only stat that I could find was adoption for HHVM[1] (a virtual machine for executing Hack and PHP[2]), but since they list Wikipedia among the HHVM adopters, I'm pretty sure this does not equate to adoption of Hack itself.
What your describing directly points to Hack Lang. Even their syntax is: <?hh
We should all take a look at Hack Lang (myself included). It could be what PHP 7 will be in a few years but is ready and available to use today. I'm watching this right now as motivation! (OSCON 2014: Include Hack - HHVM - PHP) http://www.youtube.com/watch?v=JrPGa1JDX38