Mapping on the Web
You can see it in action at:
The version you are seeing there is a demonstrator and uses the Ordnance Survey OpenSpace map server.
The OpenSpace server doesn't serve 1:25,000 scale maps and some people want that scale mapping for their web sites so they have to put the Ordnance Survey's map tiles on their own map server, usually relying on GeoServer to serve the tiles.
Here at The Hug we now have considerable expertise in doing this, having set up the Walk Highlands map server for them. They also use our mapping application, with suitable customisation, embedded in their web site. You can see that in action here (you will need to register to access the 1:25,000 scale maps - it's free to do so).
If we can help your organisation with mapping, either with a web application or with the back end server, then please get in touch.