Write documents, edit spreadsheets and create presentations on your desktop.
Free and open source (MPL-2.0).

Design & creative
Create and edit technical CAD drawings.
Create and edit technical CAD drawings.
Model 3D structures, draft precision CAD geometry and design architectural solids with free CADCraft instead of paying for SketchUp Pro licenses.
Alpha software; not hands-on tested by us. Alpha; DWG/interchange, precise geometry and production export are untested. Save, reopen and export reliability are not established; keep backups of important work.
Each comparison covers the workflow described above, rather than every paid feature.