DLL Hell Freezes Over in Whistler

Microsoft has been offering some tantalizing looks at the next version of Windows 2000 (code-named Whistler). However, the company still isn't discussing the most interesting features of this upcoming OS. Among these features is a technology called Fusion, which might solve the age-old DLL Hell problem.

DLL Hell has plagued Windows users since Windows 3.1's release and is the number-one source of Windows fragility. As users install programs over time, systems become more fragile. The decades-old Windows design, which relies on shared resources (e.g., DLLs), causes this fragile state. Various Windows versions, including Win2K, Windows Millennium Edition (Windows ME), and Windows 98 Second Edition (Win98SE), have added features to combat and resolve the problem. But Whistler, due for release in mid-2001, will extend the Fusion technology to prevent DLL Hell.

Microsoft has included earlier Fusion technology in Windows versions since Win98SE. The early Fusion technology, called side-by-side DLLs, provides a limited solution to DLL Hell. Side-by-side DLLs let an application install all or some of its shared library files into a private location in which different DLL versions coexist and work simultaneously, each serving its specific application. However, this technology requires the application to implement the feature, and because the technology is specific to Win98SE (and recent releases such as Win2K and Windows ME), few software developers have taken advantage of it.

Win2K employs another Fusion technology, Windows File Protection (WFP), which prevents overwriting key system files. Windows ME calls this feature System File Protection (SFP). WFP and SFP are effective solutions, but they prevent applications from destabilizing only the OS. They don't protect applications from one another.

Microsoft will introduce future versions of Fusion in Visual Studio (VS) and Whistler. The company plans to ship Fusion 2.0 with VS 7.0 and COM+ 2.0, which are due in the first half of 2001. To meet COM+ and Web server needs, Fusion 2.0 will automate component protection services. To satisfy consumer needs, Fusion 2.0 will provide device driver, OS installation, and OS update capabilities.

Whistler will introduce Fusion 2.5 with support for COM, COM+ 2.0, and Win32 components. Although Microsoft hasn't finalized the Fusion 2.5 feature set, Microsoft will extend Windows Installer functionality to create a virtual environment for applications running under Whistler. In this environment, each application performs as if it's the only application installed on an otherwise fresh Windows installation. The applications won't need to manually implement this feature; the OS will automatically provide it.

Whistler, which promises to offer user interface (UI) simplicity and ease-of-use enhancements, will be more than just a pretty face. This OS will finally provide users with the reliable and stable environment they've always wanted, without requiring third-party developers to manually change the way they create applications. For users and developers alike, the extended Fusion technology will create a huge win in Whistler.