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Previous  In QGIS it is obviously possible to save projects (essentially, a list of vector and raster data, with associated visualization options such as colours etc.) for later work; I find it very handy also the “spatial bookmarks”, a simple system of tagging specific portions of the working area, to zoom quickly to one of a series of sub-areas. The layout (colours, fills etc. for each layer) can be saved as a configuration file (.map) for the powerful free web mapping engine, UMN MapServer. The same data can thus be published on the web, keeping the desired layout, with minimal effort. Printing is done through a dedicated window (started with the usual click on an appropriate icon), where you can easily choose paper characteristics and scale, and inserting texts, legends and scale bars (Fig 9 [file figura_09.png]). Maps can be printed, or saved in various formats: encapsulated postscript (eps) and pdf, in raster format (bitmap, jpeg, png etc.) and in scalable vector graphics (svg). Further editing of the map can thus be carried out in different image or vector editors (among the free ones: the GIMP for rasters, Inkscape for vectors).  Projections can be handled gracefully; layers in different reference systems can be reprojected in the system of choice (over 2,700 are available) on the fly, thus avoiding to duplicate data, converting them in different systems. A modular structure: the plugins QGIS has a modular structure,, which allows to add new functionality for specific tasks. Each plugin can be activated (as usual, just a click on the menu is necessary) at the user's choice. The simplest plugins allow the user to add to the map user-defined grids (Fig 10 [file figura_10.png]), scale bar, north arrow,copyright labels and more. Others allow the import and export of geographic data from various sources:  a text file can be loaded as geographical data (points), provided it has an X and Y column (plus eventual associated data; Fig 11 [file figura_11.png])  GPS data (waypoints, routes, and tracks) can also be loaded and shown, either directly or through a text file (Fig. 12 [file figura_12.png]); QGIS uses (transparently or the user) a specialized program for this: GPSBabel (http://gpsbabel.sf.net), also free and open source software; similarly, geographical data can be uploaded on the GPS  geodatabase layers from PostGIS can also be shown, and shapefiles can be imported into the database (an icon is available for this). The GRASS plugin allows not only to display and edit GRASS layers, but also to use QGIS as a graphical interface for many GRASS commands. Activating the plugin, a window shows the commands, grouped on the basis of the function, with a graphical descrition (Fig 13 [file figura_13.png]). Clicking on one of the commands, all the relevant informations for the chosen command are shown: one window for the management of the options, one for the output messages, and one for the manual page. If for instance we need the intersection between two polygonal vectors, we just have to select the command “Vector intersection” from the group “Vector overlay”, choose the name of the two vectors to be overlayed, plus the name of the resulting vector. Then clicking on “Run” we obtain the result, which can thus be displayed on the map (Fig 14 [file figura_14.png]).   Another plugin allows the georeferencing raster images (both with linear methods, without image stretching, and with Helmert method, based on polynomials. More specialized plugins are available, generally as separate packages since they are of very specialized use. One of the most exciting features of version 0.9, now under development, is the possibility of writing plugins in python, a very simple yet powerful interpreted language. New plugins can therefore be written and tested with minimal effort. Conclusions QGIS is, right now, a modern piece of software, easy to use, and comparable to well-known Closed Source alternatives; being a young project, bugs are still present (a complete list on the QGIS web site; you can check yourself if any of these is critical for your work, and in case they are, fixing them is usually cheap and fast, if you wish to invest in the project). Features are constantly increasing, thanks to the open source development model. As an example, in the development version is now possible to save as shapefile any kind of vector layer that has been loaded into QGIS (including PostGIS, GPS, and GRASS), as a whole or a subselection of it, with a left-click on the layer name. Ultimately, as an open source project, it will be the response from developers and users (therefore, also yours) to determine the priorities and the outcomes of the next steps. Page 2 of 2
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