The context is that I found out that Firefox stopped supporting MacOS Mojave and Sierra, and it seems to me that not long ago Google stopped supporting Chrome on Windows 7.
What mainly intrigues me is that they stop supporting specific versions of an operating system, and from what I understand, Windows 10 is nothing more than Windows 7 with another skin and improved (or worsened, depending on each person’s perspective), among many more things that I will not mention, but you get my point.
That said, I know that my example is a bit exaggerated but it is a point of comparison that seems appropriate to understand my question.
Windows and MacOS release a “new OS” every few years, and Ubuntu, for example, releases a new version every year but it’s not necessarily a new OS, and also, when I go to install Firefox (or any other program) the normal thing is that I simply download an .deb, they don’t make me choose between different .deb depending on the edition or version of Ubuntu I have installed.
Even so, there are programs like AppImageLauncher that have different .deb files depending on the version of Ubuntu that is installed, including Bionic and Xenial.
From my absolute ignorance, a .deb is a .deb, just like an .exe is an .exe, but for example Mozilla can announce that it will discontinue the version of Firefox from Ubuntu 16.04 LTS backwards?
Discontinue and drop support mean different things. Runtime requirements and APIs can change in any update, even if they appear the same to users. Dropping support can be read as “you can try to make it work, but we guarantee nothing”.
The degree of success you have in coercing the package to run anyways will depend on which APIs are required, and if you can install them in your system. Windows 7 and 10 look similar, but the windows kernel has changed quite a bit between them. If it needs system access it can get hard, where if it’s dotnet or Java you just need the right runtime
A .deb relies on other packages, so a modern Firefox package will not be installable on an ancient OS. With Ubuntu Pro, Ubuntu 16.04 will still get updates until 2026, so I think you would get Firefox from Ubuntu until then. But there’s no chance you would get a modern Firefox for 7.10 or 8.04.
Maybe you should ask yourself why you would like to cling to an ancient version of Linux. You don’t like the new desktop or anything else that comes with the new version? Then you can install another desktop or another distribution.
