http://thechagosarchive.omeka.net/
Documents in the Chagos Archive are housed on the Omeka platform at the link above.
UK Government documents (1878-1971) are now available at: https://records.gov.io/
Limited Access to Other UK Government Documents
Unfortunately, documents we have on file from the UK National Archives cannot be shared publicly. If you would like access to a database of close to 100,000 UK National Archives documents for research, educational, or personal purposes, please email richardpdunne@cantab.net or chagosarchive@gmail.com. The database is hosted online on the free, open source software Zotero. For help with Zotero and more information about the UK National Archives, see below. Access to this database is generously made possible by its creator, Dr. Richard Dunne.
Help with Zotero
Quick Start Guide: https://www.zotero.org/support/quick_start_guide
Another Guide: http://libguides.newcastle.edu.au/managingyourreferences/zotero
One more: http://research.library.gsu.edu/zotero
National Archives of the British Government
UK Government documents (1878-1971) are now available at: https://records.gov.io/
Records of the British Government are released for public research purposes to the National Archives at Kew in London http://www.nationalarchives.gov.uk/. Under the Public Records Act, original government documents are transferred to the Archives after 20 years. At the National Archives, members of the public have full access to these documents and may photograph them.
The National Archives is electronically searchable on-line (http://discovery.nationalarchives.gov.uk/). A small number of files have been digitized and may be downloaded directly. The rest are in their original paper format and can only be viewed in person.