Michael Maclean demonstrates how a 2100% performance gain can be achieved when rendering a Mandelbrot fractal using Recki-CT, a PHP compiler written in PHP.

Recently, Anthony Ferrara (known throughout the Internet and beyond as @ircmaxell) and Joe Watkins (similarly well-known as @krakjoe) have been working on a new set of toys for solving this problem while staying on the “standard” PHP runtime. Recki-CT is a set of tools that implement a PHP compiler, in PHP. While this might you think of things like PyPy, which implements a Python virtual machine in Python, this is not Recki’s goal – it doesn’t provide a VM, so it can’t run PHP by itself. However, it can parse PHP code and generate other code from it.

http://mgdm.net/weblog/php-at-the-speed-of-c/