On the main PHP.net site today there's an announcement posted about the working being done on the next generation of the PHP language based on some recent discussions (and actual development work). The PHPNG branch helps boost the performance of the language to new levels and cleans up some of the core APIs.
When we aren't looking for pictures of kittens on the internet, internals developers are nearly always looking for ways to improve PHP, a few developers have a focus on performance. Over the last year, some research into the possibility of introducing JIT compilation capabilities to PHP has been conducted. During this research, the realization was made that in order to achieve optimal performance from PHP, some internal API's should be changed. This necessitated the birth of the phpng branch, initially authored by Dmitry Stogov, Xinchen Hui, and Nikita Popov.
The post talks about the performance increase of these changes (an average of 20%) and the current progress made on the internal project. This is "only the start" of the work on this new functionality, so keep an eye on the PHP.net site for more upcoming details.