This is a feature article from the August issue of GeoWorld that gives an overview of open source GIS tools. Since I have to admit that I am not that familiar with using open source stuff for GIS applications, I thought it was a good introduction.
You can read the article on Geoplace
Open Source GIS Guide
GIS Unshackled: A Guide to Open-Source Tools: a look at some of the open-source software packages, from databases to scalable vector graphics, that can be used in lieu of established commercial software. Via Very Spatial….