Open Source and free GIS: A way out?



IN PRACTICE: HOW TO TRY IT?
The vast majority of the programs outlined here gave been developed on *NIX operating systems (Unix, Linux etc.), and today GNU/Linux is generally the ideal platform for their use; many of them have been ported on other operating systems (including Microsoft Windows and MacOSX), but some of them still suffer from some limitation. Luckily, the installation of Linux is today reasonably easy , and can be done quickly with some help. Various operating systems (Linux, Mac OSX, Windows etc.) can coexist on the same PC without any side effect. The usage of simulators and virtual machines, on the other hand, is rather heavy, and does not offer significant advantages. It is also possible to have a preview of a real Linux system just using a “live” CD-ROM that, without installing anything on the hard disk (therefore not modifying any of the installed applications) starts a complete Linux machine (of course, much slower than a real one, because of the CD accession time). Some examples of GFOSS live CDs are listed at: http://grass.itc.it/download/cdrom.php. When working with GFOSS, one has to keep in mind that the community of users and developers is a fundamental resource: by the use of mailing lists, forums, web sites, chats etc., is very easy to get support. Users are encouraged to find and report bugs, that are often fixed in a very short time. Throughout the web a wide variety of manuals and how-tos are also available.

CONCLUSIONS
Is freeGIS ready to replace commercial software in real applications? The answer is articulated. To compare side by side large and complex applications is an heavy task, and few people have attempted this on a limited scale. Nevertheless, from our experience it is clear that several products are mature and ready for professional use, whereas others, while usable, need further development to be really competitive (setting aside the cost of acquisition):
  • UMN Mapserver is fully functional; it does not have significant limitations, and in several respects it is superior to its commercial counterparts
  • PostgreSQL+PosGIS as a relational geodatabase is a very reliable and powerful solution, and has already replaced commercial top-end solutions
  • for geographic analyses, GRASS is fully functional, stable and very powerful. In many situations (where money is an issue: underfunded universities and public administrations, small or heavily competing companies, etc.) it is the best alternative to the (unfortunately very common) illegal use of (cracked or stolen) proprietary software. Its inherent qualities, however, allow its use also in large and more complex settings
  • desktop mapping (and in particular QGIS) is usable, but still young; some more months of development will be necessary to make it more stable and powerful.
In addition to these programs, many others are available that can suit special needs and applications; see a list on http://freegis.org.

Tab. 1. Data formats supported by GDAL (raster) and OGR (vectors)


Figure 4 Java Unified Mapping Platform (JUMP): a free GIS programmed in Java

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