This snapshot, taken on
, shows web content acquired for preservation by The National Archives. External links, forms and search may not work in archived websites and contact details are likely to be out of date.
The UK Government Web Archive does not use cookies but some may be left in your browser from archived websites.
Essential maintenance work is being carried out on the UK Government Web Archive. This should not affect access, but in the event that it does, we will resolve it as soon as possible. We apologise for any inconvenience this might cause.
Please email if you require any assistance.



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.