I apparently missed the release of Unity 1.0 in April, but another update has been released for May, Unity 1.1.  If you are not familiar with Unity, it is a lightweight, extensible dependency injection container. It facilitates building loosely coupled applications and provides developers with the following advantages:

• Simplified object creation, especially for hierarchical object structures and dependencies
• Abstraction of requirements; this allows developers to specify dependencies at run time or in configuration and simplify management of crosscutting concerns
• Increased flexibility by deferring component configuration to the container
• Service location capability; this allows clients to store or cache the container

Unity works with .NET Framework v2.0+ and was designed to achieve the following goals:

• To promote the principles of modular design through aggressive decoupling
• To raise awareness of the need to maximize testability when designing applications
• To provide a fast and lightweight dependency injection container mechanism for creating new object instances and managing existing object instances
• To expose a compact and intuitive API for developers to work with the container
• To support a wide range of code languages, with method overrides that accept generic parameters where the language supports these
• To implement attribute-driven injection for constructors, property setters, and methods of target objects
• To provide extensibility through custom and third-party container extensions
• To provide the performance required in enterprise-level line-of-business (LOB) applications

You can read an introduction to Unity here.

What is Enterprise Library?

Enterprise Library is a collection of reusable software components (application blocks) designed to assist software developers with common enterprise development challenges (such as logging, validation, caching, exception handling, and many others). Application blocks are a type of guidance encapsulating Microsoft recommended development practices; they are provided as source code plus documentation that can be used "as is," extended, or modified by developers to use on complex, enterprise-level line-of-business development projects.

Goals for Enterprise Library

Enterprise Library is a collection of application blocks intended for use by developers who build complex, enterprise-level applications. Enterprise Library is used when building applications that are typically to be deployed widely and to interoperate with other applications and systems. In addition, they generally have strict security, reliability, and performance requirements. The goals of Enterprise Library are the following:

• Consistency. All Enterprise Library application blocks feature consistent design patterns and implementation approaches.
• Extensibility. All application blocks include defined extensibility points that allow developers to customize the behavior of the application blocks by adding their own code.
• Ease of use. Enterprise Library offers numerous usability improvements, including a graphical configuration tool, a simpler installation procedure, and clearer and more complete documentation and samples.
• Integration. Enterprise Library application blocks are designed to work well together or individually.

What’s New in v4.0?

This release of Enterprise Library includes the following:

• Integration with the Unity Application Block
• Windows Management Instrumentation (WMI) 2.0 support and improved instrumentation
• Performance improvements (particularly, in the Logging Application Block)
• Pluggable Cache Managers
• Visual Studio 2008 support
• Bug fixes

Note: existing public APIs (v3.1) are still supported.

The Application Block Software Factory and the Strong Naming Guidance Package are not included in this release but are available as a separate download. Thus, there is no longer a dependency on Guidance Automation Extensions (GAX).

For the detailed list of all changes, see About This Release of Enterprise Library.

Quick Links:

– MSDN site: http://msdn.microsoft.com/entlib

– Community Forum: http://go.microsoft.com/fwlink/?LinkID=119312

– Community Extensions: http://codeplex.com/entlibcontrib