Geoinformatics is a discipline with the need to extract, collect or analyze geographical features using the favor of computer. To perform spatial analysis, computer is a must to have, as necessary as great softwares. Thanks to the born and the advancement of technology, now we can get an affordable yet qualified computer to do the analysis. The geoinformatics software? Well.. You can have a really good one, but you have to dig your pocket really deep. If you can’t afford much, then I can suggest you to use the freewares. There are many institutions in the world provide you all these softwares, you just need to google it.

OK, I did the browsing and I find tons of free softwares. Which should I use? I can’t help you in that case, mate. Because you are the one who knows which software is suit your need. But, I will help you to give the ideas on what kind of software available on the net based on : (i) downloadable for free, (ii) easy to use, and (iii) have the community you can contact to when you have a problem. Since I have the interest to work on coastal and marine environments, I limit the discussion on the software you can use for these environments.

Spatial analysis
BIOMAPPER
A complete tools available for habitat mapping purposes
MARXAN
An annealing software, helps you to minimizes the cost while meeting user-defined biodiversity targets
CLUZ
Abbreviation of Conservation Land-Use Zoning software, works nicely with ArcView GIS
GRASS GIS
A free famously complete GIS software, work under linux environment.

Image processing
SEADAS
A free ocean color analysis software, working under linux environment. They are really nice and generous, they even send you the software.
BILKO
A small size image processing software, with a giant ability. Developed since 1987 by UNESCO

Image processing and Spatial Analysis
ILWIS
You will really love this software. It provides you image processing, spatial analysis, 3D analysis. One software for all your need