Symantec Workspace Virtualization (SWV - Formerly known as Altiris SVS) provides application virtualization that helps reduce application conflicts.

Layer Definition Files (LDF) provide a powerful way to create Symantec Workspace Virtualization virtual application layers for scenarios where capturing an application install is not possible or produces inconsistent results.

One of the more popular use cases is virtualizing the browser.  Below are links to some of the more popular browser LDFs.   

Internet Explorer 6 Windows XP Isolated Layer Definition File

Internet Explorer 7 Windows XP Isolated Layer Definition File

Internet Explorer 8 Windows XP Isolated Layer Definition File

These Browser Isolated Layer Definition Files create a "Launch Layer" that can be used to invoke each browser from a layer that is isolated from the operating system.  This allows the virtualized browser layer to have its "Hide from Operating System" flag set so that all the layer registry and file system data is hidden from the Operating System.  The benefit of this configuration is that it shields the Operating System from having visibility into any of the layer content.  This can provide increased stability in cases where a virtual layer may add components or registry keys that may conflict or cause incompatibilities with applications running in the "Base" (i.e. non-virtualized applications).

Mozilla Firefox Browser 3.6.3 Layer Definition File

The Mozilla Firefox Browser 3.6.3 Layer Definition File (LDF) provides a mechanism for customers of Symantec Workspace Virtualization to create the Virtual Application Layer and package without the need to capture the installation.