Over the past two years, Facebook’s “HipHop for PHP” has reduced CPU usage on the company’s Web servers by an average of 50 percent. “The project has had a tremendous impact on Facebook. We feel the Web at large can benefit from HipHop, so we are releasing it as open source this evening in hope that it brings a new focus toward scaling large, complex Web sites with PHP,” wrote Haiping Zhao, senior server engineer at Facebook.
He explains, “HipHop programmatically transforms your PHP source code into highly optimized C++ and then uses g++ to compile it. HipHop executes the source code in a semantically equivalent manner and sacrifices some rarely used features — such as eval() — in exchange for improved performance.”
In short, the tool gives developers the programming advantages of PHP with the performance advantages of C++.