From Computer Weekly:
The National Archives [UK] has made details of 11m records available through an application interface it published today as part of an ongoing programme to get more official records online.
The API allows anyone to search for and retrieve the metadata that describes records in the archive in XML format. The data can then be used without restriction or charge. But the archive, which is simultaneously an executive agency of the Department of Justice and a government department in its own right, continues to charge £3.50 per document to retrieve actual records online.
More Info on INFOdocket or Direct from Computer Weekly
Also from the National Archives (UK)