.NET Framework 工具Tools - Ngen.exe

The Native Image Generator (Ngen.exe) is a tool that improves the performance of managed applications. Ngen.exe creates native images, which are files containing compiled processor-specific machine code, and installs them into the native image cache on the local computer. The runtime can use native images from the cache instead using the just-in-time (JIT) compiler to compile the original assembly.

Ngen.exe has changed significantly in the .NET Framework version 2.0:

Installing an assembly also installs its dependencies, simplifying the syntax of Ngen.exe.

Native images can now be shared across application domains.

A new action, update, re-creates images that have been invalidated.

Actions can be deferred for execution by a service that uses idle time on the computer to generate and install images.

Some causes of image invalidation have been eliminated.

http://msdn.microsoft.com/en-us/library/6t9t5wcf(VS.80).aspx