Escape DLL Hell

摘要

Virtualization is all the rage these days judging by the many products on the market—VMWare and Microsoft's Virtual PC, for instance—that let administrators virtualize at the OS layer. Forty percent of North American enterprises are using server virtualization, according to Forrester estimates, with support for the technology to be embedded into most server hardware by 2008. But what about applying virtualization at the application level? A number of companies are entering this emerging area, which is variously referred to as application virtualization, application isolation, application sandboxing or application streaming. No matter the name, the process involves wrapping the application in a layer that isolates it from the operating system and other applications—whatever the application does, it can't affect or be affected by other running applications. Any file or registry changes the application requires or performs are isolated and captured by the wrapper layer. The result is an application that's much easier to distribute and remove from user workstations. Although virtualized applications can be used on servers, it is more likely that OS virtualization will be done on the server side and application virtualization will be relegated to the client side.