Ask Lemmy

I don't know about "all that you'll need to use", and this might arguably considered cheating, but I'd take emacs. I think that it's safe to say that there isn't another software package that has the same degree of coverage of functionality. I use it for doing statistics notepad work, as a word processor, as a spreadsheet, as an email client, could use it as a web browser if necessary, as a version control client, for interactive diff merging, can use it as an LLM chat client, IRC client, text editor, IDE, orthodox-file-manager-style file manager, media player frontend, agenda manager, outliner etc. If I run M-x list-packages on my copy to run the package manager, it looks like I have 6,794 emacs software packages available in it.

Unless you're going to take a broader sense of "piece of software" that would let, say, a Linux distro be taken, I think that it's pretty hard to compete with.

EDIT: Maybe in the present-day world, you could manage with a Web browser, if you treat that as being a frontend to essentially all SaaS software, count that as being bundled with the Web browser. I guess you could argue that that might be broader, and you could probably function with basically nothing other than a Web browser on a thin client and get by.

EDIT2: I guess you could also make an argument that the kernel is more-essential, because without that, nothing else can run, but I assume that you're basically treating the kernel as a given and just asking about userspace software.