OpenDocument Format

No longer is the Office suite the only product that can reliably show the content of your documents. Get rid of all the issues with vendor based formats like .doc, .xls, .wpd and .ppt – thanks to ODF it has never been more easy to write software to produce or consume documents.

OpenDocument Format website
OpenDocument Campaign

The Free Software Foundation (FSF) congratulates UK Government on choosing Open Document Format
If you live in the UK, you’ll soon be able to fill out government paperwork with your freedoms intact. The British government announced last week that Open Document Format (ODF), HTML, and PDF will be the official file formats used by all government agencies.

https://www.fsf.org/blogs/community/fsf-congratulates-uk-government-on-choosing-open-document-format