Isn’t just awkward that you use a different app? How do you explain?
If the colleague is provoking you, a dismissal answer could be a good call, like (hypothetical case) “you use iPhone and I use Android and I don’t make a fuss about it”.
Do NOT tell anybody in the office that you use Libre Office.
If you do, you will be blamed for every problem anyone encounters.Font size looks incorrect - Carl’s fault for using libre office to edit the file (even though you never worked on that project at all).
Paper jamb in the printer - Carl’s fault for printing a document from that weird libre office program.
I got fired for saying something racist on twitter - Carl’s fault for using that weirdo libre shit.
Second this. People who don’t understand tech blame anything that’s different for their problems even if unrelated.
My usual experience with non-computer people is that they really couldn’t care less and glaze over at any discussion of software choices what so ever. I’ve given up even trying to tell them for the most part. If you’re not required to use specific software by your employer (thankfully I’m not), then just use what you want and nobody will care, at least in my experience.



