For the purposes of this document:
Open source software – software which guarantees the right to access and modify the source code, and to use, reuse and redistribute the software, with no royalty or other costs. In some cases, there can be an obligation to share code improvements with the wider community.
Reference architecture – a framework that describes the organisation and components of business, information and technology systems and how they relate.
Software interoperability – coherent exchange of data between programs and IT systems using standard formats and protocols and the ability to replace any component used with another of a similar specification while maintaining functionality.
Standard – codified knowledge providing specifications for interfaces between software, systems or the documents and data that pass between them.