Facebook’s Hip Hop Virtual Machine (HHVM), a speedy engine for PHP will not target PHP 7. PHP 7, the most-recent major PHP release, but instead will focus on Hack, a PHP spinoff.
The next long-term support release of HHVM 3.24, is due in early 2018 and will the last to commit to PHP 5 support.
The HHVM team said, trying to support both PHP 7 and Hack would lead to undesirable compromises on both fronts. We plan to decouple ourselves even more from PHP so that we can make Hack great without having to account for all the oldest, darkest corners of PHP’s design.
PHP 7 represents a substantive departure from PHP 5, changing multiple behaviors, some of which not backward-compatible. With PHP 7, the builders of HHVM want to do the same. Consequently, HHVM will not aim to target PHP 7. The HHVM team believes a clear path toward making Hack a fantastic language for web development, untethered from its PHP origins.
Facebook used HHVM for years, almost exclusively to run Hack. The language already had addressed many of PHP5’s shortcomings that PHP 7 also fixes, as well as others that it does not.
By cutting loose from PHP, the HHVM team hopes to provide developers a better, higher-performing experience with HHVM and Hack. The HHVM team has lots of features, libraries, and performance opportunities in the pipeline
Hack built on the PHP ecosystem, and Facebook has plans to make HHVM compatible with current versions of major PHP tools, such as Composer and PHPUnit.
But the eventual goal for Hack to have its own ecosystem of core frameworks. Hack tools and libraries in the works include the Hack Standard Library. TypeAssert, for converting untyped data to typed data, and an autoloader for classes, type aliases, and functions.
More information: [HHVM]