elephant wrote:lots of very specialized software are developed for XP, even Vista, in other words the most common OS.
This is the case, for example, programming software for alarm panels, or software from insurance companies.
Yes, but in at least 90% of the cases, this software can be used under Ubuntu using the Wine software which "emulates" windows (although it is not really an emulator, the nuance escapes me a bit).
Even fairly recent games go with wine, so office software shouldn't be a big problem.
At worst, for those who really don't want to go with wine, they will go into a windows virtual machine launched under virtualBox.
In any case, thanks to wine, I was able to replay a bunch of old Windows 95 games that no longer went under XP.
Basically, apart from very recent games requiring large graphics capabilities and based on DirectX, there should be no Windows software that can not be launched under Ubuntu.
Moreover, to be convinced of it, it is enough to download the ISO for free, to burn it and to test in "live CD": by starting from the CD Rom, one tests Ubuntu on his machine.
without changing anything on the hard drive. You can also request free of charge a CD of the latest version.