Editing GIS file format (section)

==History==
The first GIS installations of the 1960s, such as the [[Canada Geographic Information System]] were based on bespoke software and stored data in bespoke file structures designed for the needs of the particular project. As more of these appeared, they could be compared to find best practices and common structures.<ref name="tomlinson1976">{{cite book |last1=Tomlinson |first1=Roger F. |last2=Calkins |first2=Hugh W. |last3=Marble |first3=Duane F. |title=Computer handling of geographical data |date=1976 |publisher=UNESCO Press}}</ref> When general-purpose GIS software was developed in the 1970s and early 1980s, including programs from academic labs such as the [[Harvard Laboratory for Computer Graphics and Spatial Analysis]], government agencies (e.g., the [[Map Overlay and Statistical System]] (MOSS) developed by the U.S. [[United States Fish and Wildlife Service|Fish & Wildlife Service]] and [[Bureau of Land Management]]), and new GIS software companies such as [[Esri]] and [[Intergraph]], each program was built around its own proprietary (and often secret) file format.<ref name="chrisman2006">{{cite book |last1=Chrisman |first1=Nick |title=Charting the Unknown: How Computer Mapping at Harvard Became GIS |date=2006 |publisher=Esri Press |isbn=978-1-58948-118-3}}</ref> Since each GIS installation was effectively isolated from all others, interchange between them was not a major consideration.

By the early 1990s, the proliferation of GIS worldwide and an increasing need for sharing data, soon accelerated by the emergence of the [[World Wide Web]] and [[spatial data infrastructure]]s, led to the need for interoperable data and standard formats. An early attempt at standardization was the U.S. [[Spatial Data Transfer Standard]], released in 1994 and designed to encode the wide variety of federal government data.<ref name="SDTS">{{cite web |title=Spatial Data Transfer Standard |url=https://www.usgs.gov/publications/spatial-data-transfer-standard-sdts |publisher=USGS |doi=10.3133/fs07799|access-date=6 January 2023}}</ref> Although this particular format failed to garner widespread support, it led to other standardization efforts, especially the [[Open Geospatial Consortium]] (OGC), which has developed or adopted several vendor-neutral standards, some of which have been adopted by the [[International Standards Organization]] (ISO).<ref name="OGC">{{cite web |title=OGC Standards |url=https://www.ogc.org/docs/is |website=Open Geospatial Consortium |publisher=OGC |access-date=6 January 2023}}</ref>

Another development in the 1990s was the public release of proprietary file formats by GIS software vendors, enabling them to be used by other software. The most notable example of this was the publication of the Esri [[Shapefile]] format,<ref name="shapefile">{{cite web |title=ESRI Shapefile Technical Description |url=https://www.esri.com/content/dam/esrisites/sitecore-archive/Files/Pdfs/library/whitepapers/pdfs/shapefile.pdf |website=Esri Technical Library |publisher=Esri |access-date=6 January 2023 |date=July 1998}}</ref> which by the late 1990s had become the most popular ''de facto'' standard for data sharing by the entire geospatial industry.<ref name="lo-yeung2002">{{cite book |last1=Lo |first1=Chor Pang |last2=Yeung |first2=Albert K.W. |title=Concepts and Techniques of Geographic Information Systems |date=2002 |publisher=Prentice Hall |isbn=0-13-080427-4 |page=185}}</ref> When proprietary formats were not shared (for example, the ESRI ARC/INFO coverage), software developers frequently reverse-engineered them to enable import and export in other software, further facilitating data exchange. One result of this was the emergence of [[free and open-source software]] [[Library (computer science)|libraries]], such as the [[GDAL|Geospatial Data Abstraction Library (GDAL)]], which have greatly facilitated the integration of spatial data in any format into a variety of software.<ref>{{cite web |title=Software using GDAL |url=https://gdal.org/software_using_gdal.html |website=Geographic Data Abstraction Library |publisher=OSGEO |access-date=6 January 2023}}</ref>

During the 2000s, the need for specialized spatial files was reduced somewhat by the emergence of [[spatial database]]s, which incorporated spatial data into general-purpose relational databases. However, new file formats have continued to appear, especially with the proliferation of web mapping; formats such as the [[Keyhole Markup Language]] (KML) and [[GeoJSON]] can be more easily integrated into web development languages than traditional GIS files.