active server pages (ASP)
Many users think of Web pages as being like pages in
a book, stored intact on the server, ready to be flipped
through with the mouse. Increasingly, however, Web pages
are dynamic—they do not actually exist until the user
requests them, and their content is determined largely by
what the user requests. This demand for greater interactiv-
ity and customization of Web content tends to fall first on
the server.
and on “server side” programs to provide such functions as
database access. One major platform for developing Web
services is Microsoft’s Active Server Pages (ASP).
In ASP programmers work with built-in objects that rep-
resent basic Web page functions. The RecordSet object can
provide access to a variety of databases; the Response object
can be invoked to display text in response to a user action;
and the Session object provides variables that can be used
to store information about previous user actions such as
adding items to a shopping cart.
Control of the behavior of the objects within the Web
page and session was originally handled by code written
in a scripting language such as VBScript and embedded
within the HTML text .How-
ever, ASP .NET, based on Microsoft’s latest Windows
class libraries and introduced in
2002, allows Web services to be written in full-fledged
programming languages such as Visual Basic .NET and
C#, although in-page scripting can still be used. This can
provide several advantages: access to software develop-
ment tools and methodologies available for established
programming languages, better separation of program
code from the “presentational” (formatting) elements of
HTML, and the speed and security associated with com-
piled code. ASP .NET also emphasizes the increasingly
prevalent Extensible Markup Language for orga-
nizing data and sending those data between objects using
Simple Object Access Protocol .
Although ASP .NET was designed to be used with
Microsoft’s Internet Information Server (IIS) under Win-
dows, the open-source Mono project (sponsored by Novell)
implements a growing subset of the .NET classes for use on
UNIX and Linux platforms using a C# compiler with appro-
priate user interface, graphics, and database libraries.
An alternative (or complementary) approach that has
become popular in recent years reduces the load on the
Web server by avoiding having to resend an entire Web
page when only a small part actually needs to be changed.
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