The proposed architecture makes full use of not only open
source software, but also open standards. Besides the OGC WMS
and WFS protocols mentioned above, the XForms standard from
W3C (World Wide Web Consortium, 2009) is also exploited to
manage and exchange data forms. XForms is an XML-based format
designed to represent the next-generation of Web forms (Hartung
et al., 2010) and providing a number of benefits when used on
mobile devices (see http://en.wikipedia.org/wiki/XForms). Being
based on open standards, the system has an interoperable,
modular architecture where each component is closely linked to
the others but at the same time stands on its own, allowing to be
seamlessly replaced in case of need (e.g. if a new and better
product were to appear on the market). As an example, the work
of Brovelli et al. (2014) was further improved by replacing ODK
Build with the more performing XLSForm (https://opendatakit.
org/use/xlsform) for the creation of XForms-compliant forms for
data collection.