I would like to know if ALL Kubuntu releases are available in the way the Ubuntu-proper releases are at http://old-releases.ubuntu.com/releases/, from 4.10 to 20.10
I would like to take a look at some Plasma features that might have been added and then removed.
Before 15.04 there is no Plasma 5, and I have tested already the LTS releases after that. — Therefore, what mostly interests me would be the non-LTS ("normal") releases from 15.04 to 17.10. (I would take a look even at 18.10 and 19.04, but I cannot find them either.)
I have found ALL LTS VERSIONS here.
(EDIT: also, as posted in a comment below, here are recent LTS releases, starting with 16.04.)
ALL VERSIONS up to 11.10 here.
Best Answer
Kubuntu 15.04: https://web.archive.org/web/20151110133002/http://cdimage.ubuntu.com/kubuntu/releases/vivid/release/
Kubuntu 15.10: https://web.archive.org/web/20160517131813/http://cdimage.ubuntu.com/kubuntu/releases/15.10/release/
Kubuntu 16.10: https://web.archive.org/web/20170606120152/http://cdimage.ubuntu.com/kubuntu/releases/16.10/release/
Kubuntu 17.04: https://web.archive.org/web/20171222021400/http://cdimage.ubuntu.com/kubuntu/releases/17.04/release
Kubuntu 17.10: https://web.archive.org/web/20180628191845/http://cdimage.ubuntu.com/kubuntu/releases/17.10.1/release/
Kubuntu 18.10: https://web.archive.org/web/20190629160724/http://cdimage.ubuntu.com/kubuntu/releases/18.10/release/
Kubuntu 19.04: