It is never a bad idea to refresh our memory about the software available online for free (freeware, GNU licenses, etc) in our profession. I have thought that it would be a good idea to dedicate some posts in our website to that topic. So we start today with...:
Software for stereographic projection
There are several pieces of software that you'd like to check out for that purposes. Basically all of them do the same job: project, display, analise and modify orientation data on a stereonet. More in detail, you can project in equal area, or you can choose to project in equeal projection. You can choose the hemisphere (high or low), you can choose to work with a pole or with a plane projection... And of course, rose diagramas, changes in directions for palaeocurrents, etc.
As we know, that is a basic procedure in structural geology, and therefore, my first recommendation is to masterise the stereonet by hand, using (oh, yes!) drafting paper, a pencil and a paper stereonet (And a flat pin, of course*). It is not difficult at all, and it can be fun. I loved it during my degree.
OpenStereo: Reviewed in one of my articles here: http://www.structuralgeology.org/2011/01/openstereo-stereographic-software.html. So far, I am really impressed by it!
Stereonet (by Rick Allmendinger): In his website you can download not only Stereonet, but a fair amount of other useful tools. For non commercial purposes. It is my favourite one, as it works very well, and I haven't found any bugs in it. Go here: http://www.geo.cornell.edu/geology/faculty/RWA/programs.html
StereoNett: German software produced in the University of Bochum. This is the old version, but perhaps it can be still useful in some old machine... anyway the new version is Stereo32, that you find in this article, below :-) : http://www.ruhr-uni-bochum.de/hardrock/downloads.htm
Stereo32: Same software than the one mention above, but rewritten and designed for Windows 2000, XP and Vista: http://www.ruhr-uni-bochum.de/hardrock/downloads.htm
If you know more software, please mention it in the comments of this article and I will add it to the list.
Soon, more software...
* That reminds me my lessons of "Structural Geology" in the second year of my degree. I studied Geology in Spain, where the basic degrees was, and still is, 5 years. Two of my classmates had exactly the same results during a test, and the lecturer knew perfectly who copied from who: one of them presented his drafting paper without a hole in the center for the pin!!