Active Server Pages

Active Server Pages. Often abbreviated as ASP, is a server-side scripting environment developed by Microsoft for building dynamic and interactive web pages. First released in 1996, it was a core component of the Internet Information Services web server and allowed developers to embed scripts, typically written in VBScript or JScript, directly within HTML pages. This technology played a pivotal role in the early expansion of data-driven websites, enabling integration with SQL Server databases and other COM-based components on the Windows NT platform.

Overview

Active Server Pages functions as an engine that processes server-side scripts to generate HTML content sent to a client's web browser. Unlike static HTML files, ASP pages can execute logic on the server, such as querying a database or processing form data, before delivering a customized page. The technology was designed to be accessible, leveraging familiar tools like Microsoft Visual InterDev for development and tightly integrating with the broader Microsoft BackOffice server family. Its primary use case was creating dynamic business applications, intranet portals, and early e-commerce sites on the Microsoft Windows ecosystem, competing with contemporaneous technologies like Netscape's server-side JavaScript.

History

The development of Active Server Pages was initiated by Microsoft in early 1996, with its first public release arriving in December of that year as part of the Internet Information Services 3.0 for Windows NT 4.0. Its creation was a direct strategic response to the popularity of Sun Microsystems' Java servlet technology and the Common Gateway Interface used on Unix systems. A significant evolution came with the release of ASP.NET in 2002 as part of the .NET Framework, which represented a complete architectural overhaul. Prior to this, Microsoft had introduced features like ActiveX Data Objects for database access and COM+ services to enhance ASP's capabilities within the Windows DNA architecture.

Architecture

The core architecture of Active Server Pages revolves around the asp.dll ISAPI filter running within Internet Information Services. When a request for an .asp file is received, the engine parses the file, executing any script code enclosed within special `<% %>` delimiters and interacting with the Windows Server environment. A fundamental object model, including intrinsic objects like Request, Response, Session, and Application, provides access to web functionality. The technology heavily relied on the Component Object Model for extensibility, allowing developers to use pre-built ActiveX components or create custom COM objects in languages like Visual C++ or Visual Basic to encapsulate business logic.

Development and syntax

Development of ASP pages typically involved using Microsoft Visual InterDev, which provided debugging and WYSIWYG editing, though any text editor could be used. The primary scripting languages were VBScript, a lightweight variant of Visual Basic for Applications, and JScript, Microsoft's implementation of ECMAScript. Script blocks were embedded directly into HTML, and could call into ActiveX Data Objects to execute SQL commands against databases like Microsoft SQL Server or Microsoft Access. A simple page might connect to a database, perform a query using an ADO Recordset object, and then output the results within an HTML table before closing the connection.

Alternatives and evolution

Throughout its lifespan, Active Server Pages faced competition from several alternative web development platforms. These included JavaServer Pages from Sun Microsystems, PHP on the LAMP stack, and ColdFusion from Allaire Corporation. Its direct successor, ASP.NET, introduced a compiled, event-driven programming model using languages like C# and leveraged the full .NET Framework Common Language Runtime. While classic ASP is now considered legacy technology, its concepts influenced later web frameworks and it remains supported, though not actively developed, on modern versions of Internet Information Services for backward compatibility with existing applications.

Category:Microsoft application programming interfaces Category:Web server management software Category:Scripting languages Category:1996 software