Open Source & Freeware GIS

Saga GIS 2.0 was recently released (via comp.infosystems.gis) and this got me thinking about my favorite open source and freeware GIS products out there.

Last year, I held a workshop on Open Source/Freeware GIS options and Saga GIS was definitely one of the great one sthat I pointed out. The documents and data from that workshop can be found here (remember, though, that it is bound to be outdated by now and I have never had a chance yet to update it).

Here are my favorites:

This is by no means anywhere near a comprehensive list. These applications are just the ones that I use and recommend to others.

• Christine GIS --
  For basic vector viewing and merging tables with shapes, this is my favorite by far. Very easy to use and even has a scripting language.
  
• Forestry GIS (fGIS) --
  Also very good for vector viewing and lightweight vector file editing capabilities.
  
• SAGA GIS – System for Automated Geo-scientific Analysis --
  This is without a doubt my favorite application for raster creation and analysis. Completely open source.
  
• The Carbon Project --
  For those of us programming in the .NET environment, The Carbon Project is an "Open-Geospatial .NET development toolkit."
  
• Diva-GIS --
  "A free geographic information system for the analysis of biodiversity data."
  
• Quantum GIS --
  A suprisingly powerful all-around GIS application available for a variety of OS's. Recently mentioned on Spatially Adjusted.
  
• dlgv32 Pro --
  I have not had as much experience with this one but I have heard great things and so I want to include it here.
  
• ajmGeocode PE --
  I have yet to find a free batch geocoder. This is the best I have found to date. Sure it only will geocode one address at a time, but it compiles the results in a table that you can export.
  
• GeoDa - Spatial Data Analysis Software --
  I cannot say enough good things about GeoDa. In fact, I have written about it here and here. This is an incredibly user-friendly geostatistical package that comes with far better documentation than most expensive alternatives. I often turn to this application as opposed to ESRI software.
  
• Google Earth & NASA Worlwind --
  C'mon now, 3D interactive viewers like these are so fantastically wonderful that they are changing the face of GIS.
  
• Scan Magic --
  The best free remote sensing software that I have used.
  
• Sourcepole: GIS - Knoppix --
  Boot-from-CD Knoppix Linux, complete with a complete load of open source GIS applications. These are ready to run and will make even the most die-hard Windows user thinnk twice about their faith.
  
• WinTopo: Raster to Vector --
  The best free application for heads-up digitizing and includes powerful automatic digitizing algorithms.