There are many people who wish to access maps of British locations from the 19th century onwards. This could be for many reasons - modelling the growth of towns & cities or national networks such as roads and rail; genealogical pursuits; or researching land records or historical buildings, for instance.
Presently, old OS maps are available at http://www.old-maps.co.uk/, but the site is poorly designed and the maps cost a lot of money, despite the originals being out of Crown Copyright. The only other ways to get hold of this data are to purchase originals on sites such as eBay, to buy them in old bookshops, or to visit local libraries and make photocopies of the maps they hold in their collections. All of these avenues require expense for maps which have no copyright attached any more.
I feel that making this data available online for free would allow a great deal of innovation and research to take place into Britain's past much more easily.