@arturot It's not that they are available in the main Opera page, you need to know where to find them. So, you probably know what is needed to run those old versions.

You know, software companies don't exactly like people that use old versions, so why they make things easier for those people?

If someone wants to use an old version of any software, s/he should do it by itself and on her/his own risk, without expecting any support from the software makers.