Traditionally Geographic Information Systems desktop software application has been dominated by a few large companies. The main players in the provision of Geographic Information Systems are ESRI, Integraph, Mapinfo, Smallworld and Cadcorp with ESRI having by far the largest grip on the market (30-36% market share depending on the source).
These vendors constantly develop refine and develop their products both at the desktop level and on the server / database level. There is no doubt any of the GIS’s on offer from these companies have an incredibly amount of functionality and analytical capability. This is reflected in the cost of licensing to use the software which can easily run into the thousands even for a small organisation.
GIS has always had quite a tradition of readily available Open Source applications but in the last few years the Open Source GIS arena has really rocketed. There are now numerous open source applications available freely to download and use within your organisation. These Open Source Geographic Information Systems can have much the same functionality as the licensed software from the likes of ESRI and Cadcorp.
Some of the main open source GIS systems are summarised here:-
A desktop application designed to be user friendly and geared towards everyday functions such as accessing, viewing and editing GIS data. UDig is based on the JavaScript programming language and is suitable for all capabilities of users. UDig supports all data standards and runs on windows, mac and linux operating systems. UDig is a powerful GIS system analogous to ESRI ArcMap software.
Grass (Geographic Resources Analysis Support System)
Originally developed by the US Government GRASS GIS is widely used both commercially and academically. As with UDig it is a powerful system which can handle many data types and structures. It can be used for data management and visualisation as well as more advanced functions such as spatial modelling and image processing. GRASS GIS is supported by many plugins and resources to enhance its capabilities.
MapWindow GIS is an open source project which has many users and followers. It is easily edited and via its free Active X control. MapWindow GIS supports the viewing, editing and analysis capabilities most commonly needed by the average GIS user. It supports most major GIS formats. It is the intention of MapWindow GIS that users can build a GIS to suit their individual requirements without having to have the huge amount of functionality that comes with other Geographic Information Systems.
An ever growing number of functions are supported by the QGIS platform. Running on Windows, Mac, Unix or Linux operating systems QGIS is built around the need to manage, edit, analyse and display spatial information. QGIS is able to handle raster and vector data simultaneously and is suitable for most requirements.
Desktop applications are equally matched by the availability of open source database architecture.
PostGIS is the geographic extension of PostGres SQL and allows PostgresSQL to be used as a backend database for Geographic Information Systems. It is OpenGIS compliant. PostGIS is a high performance relational database suitable for many situations. To back this up in our Environmental Consultancy business we use PostGIS to store Ordnance Survey Mapping and the PostGIS database easily handles all the MasterMap data for the UK.
Spatial extensions were first introduced in MySQL 4.1 and follow the specification as set out by the Open Geospatial Consortium.