I’m hard at work on my new book, CSS3 Visual Quickstart Guide, and I’m looking to get some feedback from you, my viewing audience. As part of chapter 1, I’ll be quickly tracing the evolution of both CSS and HTML, and I put together this timeline to help to show their relative development over the last 20 years (wow, has it really been that long). The bars in this timeline are based partially on the publication of each of the standards, but also on their relative effect on the Web. For example, although CSS1 was published in 1997, it took several years to catch on. Also, obviously, as one version of a standard grew in popularity, it’s predecessor would decline, but not always evenly.
This is not to meant to be an empirically exact chart, but to give viewers a general overview of when each of the standards was in it’s prime.