Good advice, with a caveat.
I've used that suite for decades, starting with StarOffice, OpenOffice, and most recently LibreOffice. It's improved tremendously over time, and compatibility is almost 100%.
Keyword: "Almost".
Standard, simple Word docs and Excel spreadsheets work fine. But I still find some more complex ones, that rely on advanced features of the recent Microsoft suites, are not 100% compatible. The problems arise when I get a document that was created in MS-Office, I work on it in LibreOffice, and then send it back to the original creator. They open it in MS-Office, and "It doesn't look right any more."
So I agree with ShadowAce, and I DO recommend LibreOffice. With the caveat that with regard to trading documents back and forth with Microsoft users, it's advisable to "Trust But Verify".
That said, Office 2003 (with the file conversion pack for .docx, etc.) is going to have a rough time with complex modern docs too. :-)
Not only that, but if you use those features yourself, Open Orifice is going to be a slog. I do have and use OO, but also have the paid version of Softmaker Office. I think the spreadsheet is better than Calc, but I kinda like Writer better than the WP. I still use theirs sometimes though. The only place I find Excel really, uh, excels, is very large spreadsheets like hundreds of thousands of cells with array formulas, etc. Seems to handle memory and threads better. Normal spreadsheets, Planmaker is way better.