Powerpoint and Impress are more of a problem, especially if you are creating a presentation with audio.

The biggest differences are (a) each has some functions the other doesn’t, and (b) in Excel, if I remember properly, pressing takes you to the top left cell in the unfrozen section, while in Calc it takes you to cell A1.

Excel and Calc are closer to 90% compatible.

Documents formatted in one don’t always look the same in the other. The only routine problem I’ve found is in page formatting, especially line numbering.

Word and Writer are very close to 100% compatible.

I use only Writer, Calc, and Impress, so I don’t know about differences in the other modules. That’s on the order of 20 years ago (maybe just under), and I’ve never regretted the decision. I switched to LibreOffice when Microsoft switched to the ribbon, which meant I could never find what I wanted in the menus. Just a recognition there is a cost to keep these apps going for developers and distributors and using them regularly does confer a moral obligation to help out.

It doesn’t have to be as much as you’d pay Microsoft to subscribe to Office 365. I think it is important to support these projects with annual cash donations if you can’t help with programming. I do like Thunderbird as a free, open-source replacement for Outlook and don’t feel LibreOffice needs its own email app for that reason. (This is less of an issue in a text-only document.) Since they didn’t want to learn and work in LibreOffice, I had to use an older version of Word I’d bought as a standalone license for this book. For us it was too much work to try to get the documents to display and page the same way in the two word processing apps, particularly for illustrations and their captions and inserted tables. docx in Text) a no-go for that project and showed that there are some limitations to compatibility between MS Word and LibreOffice Writer. But in the past year I was collaborating on an illustrated book with two other writers using Word 2017, and font, formatting, and spacing differences when trying to edit the same chapters made LibreOffice (Opening a document file and Saving As. I use LibreOffice as a free and open-source alternative to MS Office.

Libreoffice calc portable