| DCOM Explained by Rosemary Rock-Evans Digital Press ISBN: 1555582168 Pub Date: 09/01/98

Previous | Table of Contents | Next

### Microsoft and the Internet

Microsoft’s interest in the Internet can be traced back to the Microsoft Network MSN, which supported the Internet and was launched in May 1995. The key event which marked Microsoft’s full entry into the world of the Internet, however, was the Professional Developer’s Conference in San Francisco in March 1996, subtitled “Building Internet Applications.”

At this conference Bill Gates explained Microsoft’s strategy for the Internet. The main thrust of this strategy was that there would be:

  • one interface everywhere for file access, messages, pages, documents, and so on
  • the same metaphor for browsing the Web as that used for browsing other devices such as the hard drive of the user’s computer
  • a single standard for graphics and multimedia
  • complete integration of data and services across PCs and the Internet

What does all this mean?

In effect, Microsoft wants to treat the Internet like any other network. The developer will continue to use Windows as the client interface in the Microsoft world, but the interface within Windows will be adapted so that Web access, remote access from Windows to other machines, and local access will appear to be the same.

This is a fundamentally different philosophy to what we saw with our other middleware vendors. Java has no real place in the scheme of things here other than as an alternative language in which to develop components. There will be no Java middleware downloaded to a browser to perform connectivity and no Java interface.

The main concrete changes which were to take place as a result of the Internet strategy we saw earlier were that:

  • Explorer would be used as the single unified interface to Windows-We saw how this would work when we looked at Distributed File Systems in an earlier chapter. The Microsoft Explorer and Internet Explorer interface were being merged in Internet Explorer 4.0.
  • Existing Windows technologies would be Web enabled-From the same interface, Microsoft envisaged that a user would be able to invoke Java applets, invoke ActiveX components (objects, controls, or documents) and display pictures or data generated by other applications including Office, Exchange, SQL Server, and so on.
  • All Microsoft’s client operating systems will be given this same interface. Eventually, Windows NT Workstation and Windows 95 will be browser based.
  • HTML would be used as a Windows standard, and Microsoft would extend Windows and provide tools to ensure that this became reality.
  • ActiveX (which was announced at this conference) would become the key to component-based development both over the Web and within a company. ActiveX would bring together OLE, OCX, and VBX technologies.
  • The Internet Developer’s kit was launched.

Microsoft already had a series of initiatives going at the time of the announcement—the code name for the whole spread of technology initiatives being “Sweeper.” Sweeper covered ActiveX, unified browsing, Internet protocol support, and so on.

We now explore this approach more by looking in more detail at Microsoft’s Web browser and Microsoft’s Web server.

Microsoft Internet Explorer

Microsoft Internet Explorer is Microsoft’s Web browser. Internet Explorer can support Microsoft’s Java Virtual Machine and can run on Windows 3, Windows NT, Windows 95, and the Macintosh.

Internet Explorer started life as a version of NCSXs Mosaic—once the dominant Web browser. It was launched in August 1995. Initially, it was bundled with the Plus add-on pack for Windows 95, but as Netscape started to grow and take a larger slice of the market, Microsoft devoted more effort to its development and Explorers 2 and 3 followed in quick succession.

Internet Explorer version 3 was placed in beta test in June 1996 and was the first truly distinctive/separate version of the product. This version added support for VB Script and ActiveX controls, as well as Java applets. These three points are important:

  • With this version of Internet Explorer, the developer could create scripts which could be used to access elements of a page/document and change the elements using VBScript. We will be saying more about this in the next section.
  • The same version allowed a download of the normal Java applets in the same way we have seen earlier in the description of Java.
  • It also enabled ActiveX controls to be downloaded. This is especially important.

Microsoft uses the term Active Desktop to describe the resulting client environment. The underlying desktop is browser based, but ActiveX controls can be downloaded and equally important can operate outside the sandbox. Thus, ActiveX controls can operate with ActiveX controls within the browser and ActiveX controls outside the browser in the user’s desktop environment. Java applets can also communicate with Active X controls on a Web page.

Figure 12.4 ActiveX controls can be downloaded to communicate with ActiveX controls outside the Web browser

It is possible, for example, to use an ActiveX wrapper (written in Java) around a Java component to download a Java component which is then run using Microsoft’s JVM. Visual J++ can be used to create ActiveX wrappers for Java components.

If the machines are capable of running the ActiveX component, a binary version of an ActiveX component in some other language can also be downloaded to run on the client machine. Once the controls have been downloaded, they intercommunicate with each other using DCOM.

Thus, it is possible to have precompiled ActiveX components in different languages from Java. They could be in C++, for example, to be preloaded onto the machine and for them to communicate with wrapped Java applets and downloaded ActiveX controls.

I will have more to say about this in the chapter on security.

Previous | Table of Contents | Next