Although I rely heavily on Google Docs, it's not the only office suite I use. There are many times throughout the day when I have to depend on a locally installed office suite to do specific things. One such instance is when I am collaborating with editors who are using MS Office, and the document cannot be trusted to go through the Google Drive reformatting from .docx to the Google format and back again. In those situations, I depend on an open-source, free office suite, named LibreOffice.
I've been using LibreOffice for a long time and have found it to be as solid a tool as any on the market. Even better, it plays verywell with MS Office, so you can collaborate all you want and no one will know the difference.
LibreOffice includes:
LibreOffice includes a user-configurable interface, so you can configure it as a modern ribbon-like UI or a traditional menu-based UI (or some variation between the two). This office suite is free to use and install on as many computers as you need. There are versions for Linux, macOS, and Windows -- and it's simple to install