Defining Open

Defining Open

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  DEFINING By Richard Kachelriess,Esri Product Marketing What is open? It’s a deceptively simple question. Open is a term that’s thrown Just because data is open doesn’t mean that it is easily accessible. around in the GIS industry and in the technology industry in gen- Open data can still be stored in formats that are proprietary or rarely eral: open systems versus open source; open source versus open used and can be difficult to access. To be truly beneficial, open data standards; open standards versus open specifications. This can should be stored using an open or established specification, such as quickly become confusing. To clear up some of this confusion, this shapefiles or file geodatabase specifications, or be accessible via an article explains the differences between open technologies, how open or established standard service such as the ArcGIS map service they are related, and how they relate to ArcGIS and the GIS industry. definition, Web Map Service (WMS), or Web Feature Service (WFS). Fortunately, every variation on the open theme can be placed into one of three categories: open source, open data, or open systems. Open Systems Open systems, also known as open platforms, bring together pro- Open Source grams, operating systems, hardware, and datasets. These are com- Open source software is just that—software. The only difference puter systems and platforms that support integrating data and other between open and closed (or proprietary) source software is that systems using established standards and specifications as well as with open source, the code used to create the program is freely avail- support modifications via extensions and customizations. A system able for anyone to view, edit, and redistribute. Any type of software does not need to be open source to be open, and the standards and can be open source software. The type of license under which it is specifications used may or may not also be open source. released determines if it is open source. Examples of open source For example, many specifications for document file formats are licenses include the Apache 2.0 license, the Microsoft Public license, not open. Adobe Acrobat can be called an open system because and the GNU General Public license. portable document files (PDFs) can be created and read by many software applications. However, it is not open source, or even com- Open Data pletely open, because only Adobe Acrobat can truly edit a PDF. Open data is information that is freely available for anyone to use However, the PDF has been universally adopted for the electronic and reuse. Data is completely open if there are no restrictions on transmission of official documents because it is easy to create and its use for public, private, nonprofit research, or commercial ap- read documents but difficult to edit them. plications. OpenStreetMap is the quintessential open data GIS Open systems integrate hardware as well as software. Modern project. Its goal is the creation of a free editable map of the entire plug-and-play technology allows virtually any device to be connectd world. The data from this project is available under the Creative to a computer—printer, external hard drive, webcam, GPS device, Commons Attribution-ShareAlike 2.0 license that allows users to cell phone, headset—and it will be instantly recognized and acces- copy, edit, adapt, and transmit that data for any reason as long sible by your computer’s operating system. This greatly simplifies as OpenStreetMap is credited. Any edits can be redistributed the use of these devices, eliminating the need to manually install a under the same license. Many organizations use OpenStreetMap. device driver for each device before it can be accessed. While most organizations use it as a free basemap, a growing While not open source, ArcGIS is an open system. It works on a number of companies are building commercial solutions on top of wide variety of operating systems and with external software pro- OpenStreetMap data. grams and technologies. ArcGIS is designed and engineered for 36 au Summer 2012 esri.com
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  Manager’s Corner How Open Is Open? interoperability and extensibility and conforms to the open stand- Any source software, data, or system is only as open as the license ards and specifications necessary to implement enterprise systems. under which it was released. While there are many different open This open systems approach allows ArcGIS to interact with CAD and licenses, there are really only two types: permissive and restrictive raster data, geospatial files from third-party geospatial developers licenses. Permissive licenses allow organizations to redistribute under (e.g., ENVI EX), relational databases (e.g., Oracle, PostgreSQL, and a new license, while restrictive licenses do not. For example, if an or- Microsoft SQL Server), and web services (e.g., WMS, WFS). ganization modifies the source code of open source software that has Esri has created an extensive collection of developer tools that a permissive license, that organization can then generally redistribute contribute to its open systems approach. ArcGIS Runtime is the that modified software under any license but is not required to re- latest product in Esri’s line of developer solutions for creating and lease the modified source code. In contrast, if an organizaiton modi- deploying focused, stand-alone GIS applications. This collection of fies the source code of open source software with a restrictive license, GIS components and developer resources allows GIS functionality, it would be required to redistribute the software under the same li- dynamic maps, and GIS capabilities to be embedded into existing cense and make the modifications to the source code freely available. applications. It can also be used to build custom new applications. Using the ArcGIS Runtime, native applications can be built for Conclusion Java, WPF, Android, iOS, Windows Phone, and Windows Mobile. Esri continues to increase its level of participation in the open source Technology like ArcGIS Runtime allows Esri partners to build custom community. In addition to the Esri Geoportal Server and ArcGIS solutions that use the power of ArcGIS technology. Editor for OpenStreetMap, Esri has released the ArcGIS Viewer for Flex as open source software. Its source code is available on GitHub. Open Standards and Specifications Esri is planning to release the source code for the ArcGIS for iOS Open standards and specifications make up a subset of open source. and ArcGIS for Android mobile applications as open source software Although not software applications, standards and specifications soon. The Open Geospatial Consortium, Inc. (OGC), is an interna- provide blueprints for data formats and Internet services. When tional organization that develops and governs open standards for these are open, the information to create, modify, and interact with geospatial data, services, processes, and data sharing. Esri is a prin- formats and services is freely available for anyone to use, edit, and cipal member of OGC and actively participates in the development redistribute, allowing organizations to integrate these formats and and implementation of many of these standards. services into their applications. Without these established standards, Open is more than just open source software or open data or open interoperability between systems would be impossible. systems—it requires all these components. Integration can’t easily The difference between open standards and open specifications occur unless software uses established data formats and services. A is vague at best. Generally, an open standard is an open specification system is useless without input and output data. An open technol- that has achieved wide industry use and is governed by an organiza- ogy approach means using the best combination of open source tion made up of representatives from a majority of the competing software, data, and standards and specifications with proprietary organizations within the industry. Esri’s shapefile format, a good ex- source software, data, standards, and specifications to build the best ample of an open specification, is still governed solely by Esri, but it system possible. Esri is committed to promoting an open technology has been almost universally adopted within the GIS industry. approach with ArcGIS. For more information, visit esri.com/open. esri.com Summer 2012 au 37