微软的免费开源项目“企业库 4.0”，支持.net Framework 3.5
很好的项目范例，并且可以用在自己的项目中
Enterprise Library is a collection of reusable application blocks designed to assist developers with common enterprise development challenges. This release includes: Caching, Cryptography, Data Access, Exception Handling, Logging, Policy Injection, Security, Validation, and Unity Application Blocks.
企业库（Enterprise Library）是一个用来协助开发者完成一般企业开发要求的，可重用的应用程序块的集合 ，2008年5月发布的4.0 release 版包括：
Caching Blocks;
Cryptography Blocks;
Data Access Blocks;
Excepting Handing Blocks;
Logging Blocks;
Policy Injection Blocks;
Security Blocks;
Validation Blocks;
Unity Application Blocks;
这个Release版本包括以下特性：
- Support for Visual Studio 2008.
- Integration with the Unity dependency injection container.
- WMI2 support and improved instrumentation.
- Support for pluggable cache managers.
- Performance improvements.
下载地址：下载Enterprise Library 4.0 - May 2008