Welcome, First time Users of GRASS!GRASS GIS (Geographic Resources Analysis Support System) is a Geographical Information System (GIS) with raster, topological vector, image processing, and graphics production functionality. If you like to get a general idea about GRASS, please read this short description. GRASS is released under GNU General Public License (GPL). If you are not sure about the differences between public domain software, Free Software and proprietary products, have a look at this graph describing Categories of Free and Non-Free Software. Eventually you also want to read: Why Open Source Software / Free Software (OSS/FS)?. This article from David A. Wheeler tells you why.
The GRASS Wiki
Some new users questions
Under which platforms can you work with GRASS
GRASS is developed in a UNIX environment and is ported to many other systems like:
What can I do with GRASS? - Some examples
Does GRASS support SQL databases?GRASS can be used for vast amounts of useful work without needing an external database installed at all. Specifically if you have data with multiple attributes (e.g. in a DBF file exported from other GIS or database software) and wish to manipulate the data using queries on these multiple attributes, you may find it useful to use an external database. In GRASS 5.0/5.3 there are drivers for ODBC and PostgreSQL (see the related GRASS/SQL page).
In GRASS 6 it becomes really exciting and also includes native support for DBF files. But this system is not yet fully implemented.
What do I need to run GRASS GIS?You either need a standard PC or a workstation running a UNIX-like operating system with X-Windows (Openwin, KDE, GNOME, fvwm2, ...), e.g.: Linux (Intel or PowerPC), Solaris (SPARC or Intel), HP-UX (HP PA-RISC), FreeBSD (Intel, Alpha AXP), Mac OS X (PowerPC), or another UNIX-compliant system or MS-Windows (NT/2000/XP with cygwin) for the experimental native winGRASS port.
NOTE: You can also install Linux or another operating system in its own hard drive partition and run a Windows system parallel in another hard drive partition.
Looking for the GRASS software to download?
Well, I can't get my GIS data into GRASS! What now?
The GRASS Documentation Project
What are LOCATIONs and MAPSETs?A LOCATION is some geographic extent of interest that contains data sets that [should] all be in the same coordinate system. Every location has a PERMANENT directory which stores some basic information about the whole location, and is a good place to park base files. You can think of a location as a data library for a region of interest.
In a MAPSET you can organize GIS maps thematically or geographically or by project or whatever. Every GRASS session runs under the name of a MAPSET. A MAPSET may be a geographical subset or as large as the parent LOCATION. Technically they are subdirectories under any location. In a networked environment with several users working within the same location, mapsets play a special role. Users may only select (and thus modify) a mapset that they own (i.e., have created). However, data in all mapsets for a given location can be read by anyone (unless prevented by UNIX file permissions). The "PERMANENT" mapset usually contains the read-only base maps like the elevation model, while the other locations are readable and writable by their owners. The "PERMANENT" mapset also contains some information about the location itself that is not found in other mapsets (projection info etc.), thus it must exist in every location.
Looking for GRASS tutorials or sample data?
I know GIS already and want to program within the GRASS environment
I downloaded GRASS - but what now?
Last change: $Date: 2010-07-28 15:43:43 -0700 (Wed, 28 Jul 2010) $
$Author: neteler $