GIS software encompasses a broad range of applications which involve the use of a combination of digital maps and georeferenced data. GIS software can be sorted into different categories. The development of open source GIS software has—in terms of software history—a long tradition with the appearance of a first system in 1978. Numerous systems are available which cover all sectors of geospatial data handling. Apart from Desktop GIS exists a variety of other GIS software types. For its categorization see GIS software. A general overview of GIS software projects for each category was done in 2012. Below is a similar listing of open source GIS projects. Note: Almost all of the below companies offer Desktop GIS and WebMap Server products. Some[which?] offer Spatial DBMS products as well. Many suppliers are now starting to offer Internet based services as well as or instead of downloadable software and/or data. These can be free, funded by advertising or paid for on subscription, they split into three areas: Source.