Léo Lefebvre · CC BY 3.0

Helped transform PHP from an early collection of web tools into a general-purpose scripting language. With Andi Gutmans, he created the parser used in PHP 3, then developed the Zend Engine and co-founded Zend Technologies in 1999. As its chief technology officer, he contributed to the language and its development tools over two decades. He was nominated for the Free Software Foundation Award for the Advancement of Free Software in 1999.