Some of you likely worked through the “CSS3” thing. It was huge. People damn near stopped saying “CSS” for a few years there. Everything was “HTML5” and “CSS3”, such was the success of that marketing effort. There was a logo and everything. It was a little cheesy, but it was a good thing. People saw them as a milestone. Something that was well defined that they could wrap their heads around and learn. Then we never repeated it. In fact, the message was clear:
There has never been a CSS4. There will never be a CSS4. CSS4 is not a thing that exists.
But things tend to change over a decade, and after a couple of rounds of enthusiasm that fizzled out, there is some more official-feeling momentum on this.
- CSS4: Properties and features introduced in a spec around 2013 – 2018.
- CSS5: Properties and features introduced in a spec around 2019 – 2024.
We can’t just call everything after CSS3 “CSS4” because it’s just… too much. Flexbox ain’t exactly new. So we’ll put that and stuff of it’s era into a “CSS4” bucket, and then put a lot of the newer stuff into a “CSS5” bucket, and anything newer than that into a “Future/Next” bucket until it gets sectioned off.
I’m cool with it, let’s do it. I don’t even wanna bikeshed what goes where, just ship it.
