Complex sentence: Former or current employees of Happy Cog have popularized such ideas as CSS layout, responsive design, and style switching, an early 2000s technique paving the way for later third-party innovations including CSS Zen Garden and Readability.
Split into simpler sentences: Former or current employees of Happy Cog have popularized such ideas as CSS layout, responsive design, and style switching. The latter was an early 2000 innovation which paved the way for later third-party innovations including CSS Zen Garden and Readability.