Microsoft's IIS 3.0 Catche s Up By Anthony Frey   It's well known that Microsoft Corp.'s Internet Information Server (IIS) and Netscape Communications Corp.'s Enterprise Server have been running neck and neck for all-out performance. But as far as application development, previous versions of IIS have been limited to Common Gateway Interfaces (CGIs), Microsoft's Internet Server API (ISAPI) and the rudimentary Internet Database Connector (IDC). The recent release of IIS 3.0 Beta 2, formerly code-named Denali, gave us a chance to see how Microsoft is leveraging its ActiveX components to address these shortcomings. For the core HTTP services and performance, we'll compare IIS 3.0 and other Web s ervers in the February 15 issue. In terms of intranet development, however, it's safe to say these improvements warrant a more serious consideration of IIS than simply "the free Web server that comes with Windows NT." Active Everything The real improvement with IIS 3.0 comes in what Microsoft is calling Active Server Pages (ASP). However, we found ASP is nothing more than a Windows Dynamic Link Library (DLL) that implements server-side scripting. There are many third-party solutions that use ISAPI to do other kinds of server-side processing (for example, database access using extended HTML tags). More important, ASP provides a nearly complete interface to Microsoft's ActiveX and Component Object Model (COM) technologies. ASP sets up a framework around the core IIS HTTP server, from which you can hang a comprehensive Web application environment with a consistent execution model from client to server. Rather than define the server-side scripting language, ASP provides a COM interface for more gene ral-purpose scripting engines. ASP is triggered by files with the .asp file extension. Within these files, anything between the <%, %> tags is subject to server-side processing. By default, the processor is VBScript, but you can use JScript just as easily. When we used either VBScript or JScript, we could easily retarget execution with a command such as <SCRIPT LANGUAGE=JScript RUNAT=Server>. ASP includes a set of intrinsic objects (Server, Application, Session, Request and Response) that effectively defines the application's execution environment between the client and server. These objects are almost identical to the set of objects defined by Netscape's LiveWire, and they include variables for state and session management, client cookies and HTTP headers. ASP also has a base set of ActiveX components that let you perform ad rotation (commonly used for advertisements, ad rotators alternate a set of images for each successive Web page hit), access the file system, retrieve browse r capabilities, access Open Database Connectivity (ODBC) data sources and manage page links. We had difficulty getting the file system object to instantiate at the time of this beta release. Together, the bundled components don't provide a definitive tool set, but they do satisfy a few crucial needs for developing Web-based ActiveX applications. The key to efficient database access from the Web is caching the database connections. By utilizing the intrinsic Session object that IIS creates to track user sessions, we saved database connections variables for use in later queries. Although not quite as automatic as LiveWire from Netscape (in other words, we had to save session variables, whereas with LiveWire we did not), the interface was logical and simple to use. Microsoft rounds out IIS 3.0 with a set of useful server options: Index Server, NetShow and FrontPage Server Extensions. These packages are separate from ASP and complement Web applications such as indexing searchable documents, streaming medi a and Web document publishing. The most obvious advantage of the ASP framework is its flexibility. Microsoft has hedged its ActiveX bet by letting the intranet developer choose VBScript, JScript, server-side Java or all three as the de velopment environment. But if you select JScript or server-side Java, you could deliver ActiveX programs to the client whose binaries are limited to running on Intel Corp. PCs and are a higher security risk than Java applets. Until Microsoft resolves the ActiveX portability and security issues, the ASP framework may be limited to deployment on safer intranet grounds. Those caveats aside, Microsoft provides a tremendous amount of development power with the ASP framework. Goodbye, IDC To put it bluntly, Microsoft's first crack at database integration, the IDC, was an ill-conceived solution. It had minimal functionality and was limited because it did not allow more than one database query per IDC template file. This shortcoming has been rectified quite nicely wit h the ActiveX component Active Data Objects (ADO), which is included as part of the base ASP package. We were free to create database session objects up and down the ASP scripts. Anthony Frey can be reached at afrey@nwc.com.

Xircom's CreditCard Makes the Connection by Joel Conover Updated January 24, 1997