https://www.libreoffice.org/

Well, this has to be my favourite free office suite. Available for more operating systems than you can shake a stick at.

"LibreOffice is a powerful office suite – its clean interface and feature-rich tools help you unleash your creativity and enhance your productivity.

LibreOffice includes several applications that make it the most powerful Free and Open Source office suite on the market:

  • Writer (word processing),
  • Calc (spreadsheets),
  • Impress (presentations),
  • Draw (vector graphics and flowcharts),
  • Base (databases),
  • Math (formula editing)."