Microsoft on Wednesday will take a significant step toward expanding the appeal of its .Net software plan by linking to Apache, one of the most important open-source software projects.

The software giant plans to extend .Net to the popular Apache Web server, which could give Microsoft access to a far larger audience of software developers. Apache is used by more than half of all Internet sites, according to an ongoing survey by research firm Netcraft.

Microsoft, which on Wednesday is to hold a day-long session at its Redmond, Wash., headquarters to outline its plans for .Net, is increasing its efforts to link .Net to popular, non-Microsoft software packages.

The links to Apache are expected to be announced Wednesday by Covalent Technologies, a venture-backed company that sells Apache along with support and enhancements. Covalent employs several of the central Apache programmers.

On Tuesday, Microsoft said it has developed software to link .Net to Oracle's database server.

The .Net agenda includes new releases of the company's Windows operating system and other server software, along with development tools and framework to make programs more Internet-aware. One new technology supported by .Net is Web services, which promises to make linking internal computer systems, and systems residing in multiple companies, far easier than current methods.

Although developers and analysts have given .Net high marks for its technical design, some Microsoft customers have called the company's marketing plan confusing. Microsoft simultaneously launched .Net as a rebranded version of its core products and as an ill-fated consumer Web services effort called .Net My Services the company is retooling.

Also, .Net's largely Windows-only design may be limiting its appeal. Technology buyers have told News.com that they are waiting for additional standards and better compatibility before they commit to large-scale Web services projects.

The software giant is expected to extend .Net to additional server software and operating systems in the coming months, said analysts.

Apache competes with Microsoft's own Internet Information Server along with Sun Microsystems' Sun ONE Web server. Red Hat, the top seller of Linux, includes an Apache-based Web server package called Stronghold in its products.

Covalent is expected to announce that developers using Microsoft's Visual Studio.Net tools will now be able to build links to Apache Web servers using .Net's ASP.Net software layer. ASP.Net is a specialized type of software called a class library, replacing an older technology called Active Server Pages (ASP) for creating Web applications that support new Web services technology.