On Thu, 17 Mar 2016, Carsten Kunze wrote:
For spreadsheets gnumeric is a possible light-weight alternative.
I like Gnumeric, as well. It's been solid for a very long time. I find the interface to be more straightforward than Excel, any day. I also still use 'sc' from time to time, too.
For other documents it is suggested to learn LaTeX, really. To use even plain TeX or troff is less pain than to use a office tool...
You can use Lyx for LaTeX as others have mentioned. I would also note asciidoc which has a smaller learning curve vis-a-vis TeX, but it's not quite as powerful (especially if you are doing math-heavy documentation).
-Swift