Free and Open Source Software Development in Archaeology. Two interrelated case studies: gvSIG CE and Survey2GIS

This short article illustrates the growth in the use of Free and Open Source Software (FOSS) GIS tools in European archaeology. It draws mainly on the experience gained using the programs gvSIG CE and Survey2GIS. It demonstrates the advantages of open source software for archaeological research and fieldwork, while not ignoring the pitfalls and hazards to be avoided in the FOSS world.

This extended abstract is also available in hard copy in K. May (ed) 2017 Digital Archaeological Heritage, EAC Occasional Paper No.12, Archaeolingua, Budapest.

This abstract illustrates the use of open source GIS tools in European archaeology, drawing on the experience gained using the programs gvSIG, gvSIG-CE and Survey2GIS by Oxford Archaeology, UK and the Landesamt für Denkmalpflege Baden-Württemberg, Germany. It demonstrates the advantages of open source software for archaeological research and fieldwork, while not ignoring the pitfalls and hazards to be avoided in the FOSS world.

Today archaeology relies on computer hardware and software but the potential of 'Free and Open Source Software' (FOSS) has not yet been fully realised by archaeology and related disciplines. However, open source applications for GIS are readily available and these can be well employed in archaeological fieldwork and research. This abstract looks at two FOSS programs and analyses their potential in this respect. The programs gvSIG-CE and Survey2GIS are both published under the GNU General Public License (GPL; https://gnu.org/licenses/gpl.html), for FOSS is neither 'freeware' nor 'shareware', even though the license terms are liberal. Both these programs have helped the Landesamt für Denkmalpflege Baden-Württemberg (State Cultural Heritage Department, Baden-Württemberg) to rethink its habitual acceptance of the 'pay-per-license' model and aided it in offsetting the prohibitively high costs of replacing outdated commercial software, hardware and operating systems and changes in proprietary licensing models that were due at the end of the first decade of the 21st century. In fact, the Landesamt's hand was forced and it started its own open source development in the form of Survey2GIS (http://www.survey-tools.org). Survey2GIS has become a successful piece of surveying software, at the time of writing, well past the BETA stage, it is in action in the field across the state of Baden-Württemberg and beyond. An unexpected but gratifying aspect of the development of Survey2GIS is not just the speedy and simple transfer of survey data into GIS but also the new 'data-centricity' of the fieldwork and research which it has made possible. With Survey2GIS it is possible to adapt the method to the project, rather than approaching projects to suit the software.

Survey2GIS, although a completely autonomous program, comes from the same 'stable' as gvSIG-CE (http://csgis.de/gvsigce), itself a fork of gvSIG, Open Source software originally developed on behalf of Generalitat Valencia Sistema de Información Geográfica, Spain (http://www.gvsig.com). Soon after its inception, gvSIG was quickly and enthusiastically adopted by Oxford Archaeology as the core element of its FOSS GIS migration. While travelling further and further down the gvSIG road, Oxford Archaeology began to realise the inadequacies for archaeology of the native version of gvSIG. With no possibility of turning back, Oxford Archaeology had little choice but to continue independent development of gvSIG for its own requirements (made possible by the fundamental FOSS ethos of open program code). The result was the gvSIG OADE 2010 (Oxford Archaeology Edition), still popular with archaeologists today. GvSIG OADE 2010 ultimately lead to the development gvSIG Community Edition. At the time of writing the 64-bit version is vital, well developed and (alongside Quantum GIS) established as an important tool in both the Landesamt für Denkmalpflege Baden-Württemberg and the Bayerisches Landesamt für Denkmalpflege (State Cultural Heritage Department, Bavaria).

Survey2GIS is a light-weight FOSS tool for use in field documentation and surveying which functions both as a plugin from within gvSIG-CE and also as a standalone program processing surveying data for any preferred desktop GIS. It has been under development since 2011/2012 and available in version 1.3.3 at the time of writing. A central element in the Landesamt für Denkmalpflege's strategy in developing Survey2GIS was the transition of topographic survey activities from proprietary CAD to (FOSS) GIS (gvSIG CE and Q-GIS). To make this possible, a new software had to be devised to act as the link between the surveying hardware and the GIS software. The result was the development of Survey2GIS. Survey2GIS is a fully developed, compact and flexible solution for handling topographic survey data. It processes 2D or 3D point measurements into geometrical objects, including multipart features and polygons with holes. Input data consist of one or more survey data files with coded coordinates. The output generated by Survey2GIS is ideal for direct use in GIS. The process can be fully steered by the user, allowing flexible adaptation to individual survey workflows and data structures. Input and output formats can be adapted to fit the requirements and constraints of virtually any project. During its development, high priority has been given to the generation of topologically correct output, suitable for quantitative analysis in GIS. Survey2gis is highly customisable and includes a number of features designed to boost productivity in the field. This is a significant return on investment, often overlooked when comparing the license-fee savings against the cost of open-source software development and staff training.

This abstract does not intend to condemn either proprietary software or traditional business models. FOSS and proprietary software coexist and will continue to do so for the forseeable future. However, excessive or fluctuating license fees, cloud solutions, the risk of vendor lock-in and a lack of shared investment options should open the minds of those in research and education to consider alternatives. The case studies show that at least one large and important authority in German archaeology, echoing a solution initiated by Oxford Archaeology some years earlier, has in the case of Survey2GIS recently put this into practice.