In 2003 nobody was using CSS beyond controlling basic fonts and colours. Those who understood its capabilities were rarely designers, and designers largely hadn't embraced it yet.
And so the perception spread that CSS was only capable of boxy and boring design. And those who understood what it was truly capable of were unable to convince their clients and their teams to take the necessary risks required to use it.
It was around this time that Jeffrey Zeldman brought a classic writing principle of 'show, don't tell' over to the web and encouraged those of us who wanted the situation to change to stop talking about what CSS could do, and start doing it already.
Inspired by this idea, I created a site with the goal of being a collaborative gallery that would show what CSS could accomplish. The simple requirement: a designer was unable to modify the HTML in any way, the entire design had to be accomplished through CSS and images alone.
I designed the CSS Zen Garden as a community site from the beginning. Including work from other talented designers was meant to encourage more designs than I could produce on my own.
Both the collaborative nature as well as the visual demonstration of CSS worked together to drive home the argument that CSS-based design was finally ready for prime time. In that regard, it worked better than I could have hoped, becoming an international success almost immediately. With thousands of designs submitted from over 30 countries, the site has been translated into 22 languages and spawned a book that has been translated into a dozen languages itself.
Over 12 years since it launched, the designs it contains span a formative period of web design and development and has frequently been referenced in web curriculums for over a decade. While some of my other projects have been popular in various ways, none has had as much impact as this one. It was a landmark project that helped advance my own career, as well as the careers of the many designers whose work helped build it over the years.