Split into two articles This article is in an odd state because it covers two completely separate projects 1 HipHop for PHP or HPHPc a PHP to C transcompiler and 2 HHVM or the HipHop Virtual Machine a PHP virtual machine that share nothing other than part of their names and Facebook s sponsorship I d like to split the article the current article would remain and describe the HipHop for PHP project consisting of the HPHPc transcompiler and HPHPi interpreter from its infancy in 2008 until its abandonment in 2013 but the content describing the virtual machine from its genesis in 2010 until the present would be moved to an article titled HHVM Since the naming situation is fairly confusing I ve added some reference quotes below Thoughts Primary no parenthetical names for these projects are bolded and suffixed with a number describing whether they refer to 1 the transcompiler or 2 the virtual machine Today I m excited to share the project a small team of amazing people and I have been working on for the past two years HipHop for PHP 1 We have also developed HPHPi which is an experimental interpreter designed for development Facebook blog Feb 2010 That s how Facebook explains the significance of its new PHP executor HipHop Virtual Machine 2 HHVM 2 will improve the performance of Facebook s code Facebook originally deployed its open source HipHop for PHP 1 in February 2010 Techcrunch Dec 2011 In late 2011 we announced that we were pursuing a just in time JIT compilation approach called HipHop VM 2 HHVM as a successor to the HipHop PHP to C compiler 1 HPHPc We are happy to announce that HHVM 2 is now as fast as HPHPc 1 Facebook blog Nov 2012 Facebook has been using the virtual machine called the HHVM 2 HipHop Virtual Machine across all of its servers since earlier this year Facebook originally devised a compiler called HipHop 1 that would translate PHP code into C The previous HipHop renamed HPHPc 1 has now been retired within Facebook Javaworld Jul 2013 In 2010 Facebook rolled out a tool called HipHop 1 the trio agreed that Facebook could take PHP performance to an even higher level if they replaced HipHop with something called a virtual machine In a nod to the company s original PHP converter they called the system the HipHop Virtual Machine 2 or HHVM 2 for short Wired Jul 2013 Facebook has also made great progress on its alternative open source PHP engine the HipHop Virtual Machine 2 HHVM HHVM 2 uses O Reilly Programming Mar 2014 Hack runs only on Facebook s HipHop virtual machine 2 HHVM Should you start learning Hack and HHVM 2 Yes O Reilly Programming Apr 2014 HHVM 2 is an open source virtual machine HHVM official website