We always aim to offer our customers the best experience possible, with the tools they want to use. Usually that means expanding the platforms and languages we support (which now stands at six languages and counting), but occasionally it means dropping tools that are not being used so that we can focus resources on those that are.
For that reason, we will be dropping support for the HHVM runtime on 1 March 2018.
HHVM began life at Facebook as a faster, more robust PHP runtime. Although it never quite reached 100% PHP compatibility it got extremely close, and did see some success and buy-in outside of Facebook itself. Its most notable achievement, however, was providing PHP itself with much-needed competition, which in turn spurred the work that resulted in the massive performance improvements of PHP 7.
Similarly, Facebook's "PHP extended" language, Hack (which ran on HHVM), has seen only limited use outside of Facebook itself but served as a test bed and proving ground for many improvements and features that have since made their way into PHP itself. Like HHVM itself, though, Hack never achieved critical mass in the marketplace outside of Facebook.
Back in September, Facebook announced that they would be continuing development of Hack as its own language, and not aiming for PHP compatibility. Essentially Hack/HHVM will be a "full fork" of the PHP language and go its own way, and no longer try to be a drop-in replacement for PHP.
Platform.sh has offered HHVM support as a PHP alternative for several years, although as in the broader market it didn't see much use and with the release of PHP 7 the performance advantage of HHVM basically disappeared, leading people to migrate back to vanilla PHP 7. Looking at our own statistics, in fact, we recently found that HHVM was virtually unused on our system.
"Give the people what they want" also means not giving them what they clearly don't want, and the PHP market clearly doesn't want HHVM at this point. We will therefore be dropping support for it on 1 March. If Hack/HHVM develops its own market in the future and there's demand for it we may look into re-adding it at that time, but we'll wait and see.
Good night, sweet HHVM, and may a herd of ElePHPants sing thee to they REST!