Introduction - Desktop GIS: Mapping the Planet with Open Source Tools - page 10

You can see an example of server-side mapping by pointing your web
browser at one of the many web mapping applications on the Internet.
These range from sites providing maps and driving directions to those
serving up massive quantities of data. I'm sure everyone has seen exam-
ples of the type of applications I'm talking about, but for Harrison's
benefit we'll mention a URL. Take a look at the Geodata.gov website 7
for some sample web mapping applications.

When using server-side mapping, we don't install anything on our local
machine, and all we need is a web browser. The good thing about this
scenario is that someone else has done all the work in assembling the
data and preparing it for display and use. Why would we want to go
the desktop route instead of letting someone else do all the work for
us? Our friend Harrison discovered some of the reasons in his bird-
mapping project. He wanted to view his data, not the data provided
by some server somewhere. He wanted to create new data by digitizing
the lakes. 8 Harrison also wanted to analyze his data by buffering and
storing the results. A lot of these operations can be done with server-
side mapping, but the data ends up living on the server. If you're lucky,
there may be a way to export it and make it yours.

Am I down on server-side mapping? No—it's an excellent way to visual-
ize data and provide it to the masses. In fact, there are projects under-
way to further enable the server side and extend the capabilities to
analysis as well. 9 Using a mix of desktop and server GIS software is a
good mode of operations, especially if you are like Harrison and want
to be both a data creator and a consumer.

1.3 Assembling a Toolkit

With the preliminaries out of the way, my goal is to help you assemble
a loosely coupled toolkit of OSGIS applications. There are good reasons
to assemble a toolkit rather than using a single mapping application.
Just as you wouldn't use a screwdriver to build an entire house, we'll
get better results if we use the right tool for the job at hand. When it
comes to OSGIS, I'm a strong proponent of IIWUI—“If It Works Use It.”

7. http://geodata.gov
8. Sure, you can create features on some web mapping sites. But where do they reside
when it's all said and done? On the server.
9. An example is PyWPS ( http://pywps.wald.intevation.org ) , which allows web access to
GRASS GIS.