I see some references made about HTML6 and CSS4 on the web, but I can't make out whether these versions are already here. Are they?

No, and they never will be.

It’s now just HTML and CSS. Both of these will have new features and updates but there won’t be a new numbered version.

On 7/15/2019 at 3:43 AM, fisicx said:

No, and they never will be.

It’s now just HTML and CSS. Both of these will have new features and updates but there won’t be a new numbered version.

Correct, it's just an on-going spec now. You might see references to HTML6 and CSS4 but it's just marketing nonsense.

The biggest change is that you won't see vendor prefixes like -moz and -webkit anymore.

On 7/14/2019 at 11:40 PM, Stiphan said:

I see some references made about HTML6 and CSS4 on the web, but I can't make out whether these versions are already here. Are they?

If you are reading tutorials or taking part in courses that mention this then walk away as you'll no doubt be being fed even more mis-information.

I'm sitll waiting for web 3.0. maybe it's still in beta?

On 7/15/2019 at 12:40 AM, Stiphan said:

I see some references made about HTML6 and CSS4 on the web, but I can't make out whether these versions are already here. Are they?

Like others said above, there's no HTML6 nor CSS4. Even CSS3 doesn't exist. The last real version of CSS is 2.1. After that changes are in different modules of the spec. But the versionnumber never changed and will not change.