He is quick to play down his contribution to what PHP is today, instead attributing most of PHP's success to the vast community of developers that have signed on to the project over the years. In a sense, Rasmus today is simply PHP's biggest fan.
Looking at the usage figures, there are now over 9 million domains using PHP. Did you have any idea that PHP was going to become this big? How does it feel to know that your product is probably the best alternative to Microsoft's solutions for the Web?
RL: First, to be clear, I did not develop the PHP we know today. Dozens, if not hundreds of people, developed PHP. I was simply the first developer.
PHP is very much a collaborative project. Think of it this way: you have a Web problem. You can either go to the store and buy an expensive shrink-wrapped product that may or may not solve most of your problem. Or you can get together with a couple of thousand people who have the exact same problem as you, and work out a solution that works for all of you.
Interview - PHP's Creator, Rasmus Lerdorf [PHP & MySQL News Interviews]