Datasheet

even need a web server of your own at all. The downside, however, is clear — you are completely depen-
dent on the end user to be using a computer capable of running your mashup. You can see a typical
client-side configuration in Figure 1-1.
Figure 1-1
In a client-side mashup, the user first retrieves the web page containing the mashup. Typically, other
code within this page then executes within the client browser and retrieves further data from other web
servers on the Internet, and then integrates it into the original page, finally displaying the resulting page
to the user.
For client-side mashups to work, you need to either have the end user install all the required software, or
rely on it already being there. In most cases you can reasonably expect a user to have certain software
available — a relatively up-to-date web browser, JavaScript, maybe even the Flash plug-in. You should
remember, however, that the more demands you place on the client, the smaller the potential audience for
your mashup becomes. Many users won’t install extra software just so they can see your mashup— no
matter how good it is. Ideally, all they should need to do is point their web browsers in the right direction.
Mashing on the Server
For maximum control and flexibility, mashing on the server is usually by far the best option. You will
often have much more control as to the software available to you, installing anything that you need.
The server takes control, retrieving content from the various different sources, assembling it all, and then
sending the finished result back to the client. You can see all this in action in Figure 1-2.
Request Data
User
Web Server Web Server
Web Server
Request Data
Request Web Page
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Part I: Building a New Internet
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