On PHP.net today they've announced the released of the latest (and hopefully last) Release Candidate before the final, stable version of PHP 7 is announced: PHP 7.0.0. RC7.
The PHP development team announces the immediate availability of PHP 7.0.0 RC 7. This is the twelfth pre-release of the new PHP 7 major series. All users of PHP are encouraged to test this version carefully, and report any bugs and incompatibilities in the bug tracking system.
[...] This release candidate is unplanned and ships instead of the announced RTM for the reasons of yet additional quality improvement. If no major issues appear within the usual two-week test period, the 7.0.0 general availability (GA) release will be brought out. You can also read the full list of planned releases on our wiki.
You can find the complete list of changes in the NEWS file. You can get the download of this latest release from either the QA source download page or the windows.php.net QA site. Remember, this is a release candidate version and is not meant to be used in production.