1 # HipHop VM for PHP [![Build Status](https://travis-ci.org/facebook/hhvm.png?branch=master)](https://travis-ci.org/facebook/hhvm)
3 HipHop VM (HHVM) is a new open-source virtual machine designed for executing programs written in PHP. HHVM uses a just-in-time compilation approach to achieve superior performance while maintaining the flexibility that PHP developers are accustomed to. HipHop VM (and before it HPHPc) has realized > 5x increase in throughput for Facebook compared with Zend PHP 5.2.
5 HipHop is most commonly run as a standalone server, replacing both Apache and modphp.
9 Our [FAQ](https://github.com/facebook/hiphop-php/wiki/FAQ) has answers to many common questions about HHVM, from [general questions](https://github.com/facebook/hiphop-php/wiki/FAQ#general) to questions geared towards those that want to [use](https://github.com/facebook/hiphop-php/wiki/FAQ#users) or [contribute](https://github.com/facebook/hiphop-php/wiki/FAQ#contributors) to HHVM.
13 You can install a [prebuilt package](https://github.com/facebook/hiphop-php/wiki#installing-pre-built-packages-for-hhvm) or [compile from source](https://github.com/facebook/hiphop-php/wiki#building-hhvm).
17 You can run standalone programs just by passing them to hhvm: `hhvm my_script.php`.
19 HipHop bundles in a webserver. So if you want to run on port 80 in the current directory:
25 For anything more complicated, you'll want to make a [config.hdf](https://github.com/facebook/hiphop-php/wiki/Runtime-options#server) and run `sudo hhvm -m server -c config.hdf`.
29 We'd love to have your help in making HipHop better.
31 Before changes can be accepted a [Contributor License Agreement](http://developers.facebook.com/opensource/cla) ([pdf](https://github.com/facebook/hiphop-php/raw/master/hphp/doc/FB_Individual_CLA.pdf) - print, sign, scan, link) must be signed.
33 If you run into problems, please open an [issue](http://github.com/facebook/hiphop-php/issues), or better yet, [fork us and send a pull request](https://github.com/facebook/hiphop-php/pulls). Join us on [#hhvm on freenode](http://webchat.freenode.net/?channels=hhvm).
35 If you want to help but don't know where to start, try fixing some of the [Zend tests that don't pass](hphp/test/zend/bad). You can run them with [hphp/test/run](hphp/test/run). When they work, move them to [zend/good](hphp/test/zend/good) and send a pull request.
37 All the open issues tagged [Zend incompatibility](https://github.com/facebook/hiphop-php/issues?labels=zend+incompatibility&page=1&state=open) are real issues reported by the community in existing PHP code and [frameworks](https://github.com/facebook/hiphop-php/wiki/OSS-PHP-Frameworks-Unit-Testing:-General) that could use some attention. Please add appropriate test cases as you make changes; see [here](hphp/test) for more information. Travis-CI is integrated with this GitHub project and will provide test results automatically on all pulls.
42 HipHop VM is licensed under the PHP and Zend licenses except as otherwise noted.
46 See [Reporting Crashes](https://github.com/facebook/hiphop-php/wiki/Reporting-Crashes) for helpful tips on how to report crashes in an actionable manner.