Safari and WebKit had it from 2008 but prefixed. Chrome, back then based on WebKit pre forking it, will have had prefixed support from launch.

Firefox had it from 2006, prefixed.

IE was the holdout, not having it until v9 in 2011.

https://caniuse.com/border-radius

Yes, border-radius was available since ~2007/2008 except for IE (I remember using some hack involving HTC files, maybe CSS3PIE[0]).

[0]: http://css3pie.com/

I am referring to the image slicing technique and rendering fancy buttons and sidebar "blocks" using tables in the likes of PHP-Nuke and other content management systems of the time.

> I remember in the early days cobbling together elements with top-left, top-right, etc image slices. Want't really too long ago.. maybe 10 years?

To me this is core ajax and php era, so ~2002-2006 which would be about 18 years ago.

By the time CSS standards for rounding corners arrived a lot of pain has been inflicted on us developers, but by now it feels as if this era never existed (same with pre/post flex to take another CSS milestone)