Mash-ups are a unique user experience created by combining multiple separate media, data, or system functinality to produce a new service. One of the most common examples of a mash-up is taking images from an online repository (such as Flickr) and overlaying them on maps (such as Google Maps). Mash-ups differ from all-in-one products in the fact that instead of developing a new feature into an existing tool, they combine the existing tool with another tool that already has the desired feature. All tools work independently, but create a uniquely customized experience when used in harmony. New products can be created simply by adding additional media to the mix.
As tools become increasingly modularlized the possibilities for mash-ups are increasing exponentially. This same approach can applied to delivering learning content (see modular approach to learning management system).