Originally posted by Silvia Renn (WorldFish):
If you are looking for an “easy to use” and mostly stable open source software, I can recommend MapWindow GIS. It has all basic GIS functions and great plugins (such as a Google Earth screen shot app).
I have been using this software regularly and the nice thing is that (in comparison to many other OS packages out there) the functions actually work without crashing. It is also quite intuitive to use – QGIS is probably easier but not stable when it comes to working with larger raster files.
I also like the selection of functions MapWindow GIS has and at times I prefer using this software to the commercial one. Here is a list which will give you a good overview of what the software can do. The plugins are also worth a look!