.NET - .NET Framework

Assembly metadata is stored in Manifest. Manifest contains all the metadata needed to do the following things

• Version of assembly.
• Security identity.
• Scope of the assembly.
• Resolve references to resources and classes.

The assembly manifest can be stored in a PE file either (an .exe or) .dll with Microsoft
intermediate language (MSIL code with Microsoft intermediate language (MSIL) code or in a
stand-alone PE file, that contains only assembly manifest information.

Code contracts help you to express the code assumptions and statements stating the behavior of your code in a language-neutral way. The contracts are included in the form of pre-conditions, post-conditions and object-invariants. The contracts help you to improve-testing by enabling run-time checking, static contract verification, and documentation generation.

The System.Diagnostics.Contracts namespace contains static classes that are used to express contracts in your code.

The following two new classes are introduced in the System.Numerics namespace:

• BigInteger - Refers to a non-primitive integral type, which is used to hold a value of any size. It has no lower and upper limit, making it possible for you to perform arithmetic calculations with very large numbers, even with the numbers which cannot hold by double or long.
• Complex - Represents complex numbers and enables different arithmetic operations with complex numbers. A number represented in the form a + bi, where a is the real part, and b is the imaginary part, is a complex number.

Managed extensibility framework (MEF) is a new library that is introduced as a part of .NET 4.0 and Silverlight 4. It helps in extending your application by providing greater reuse of applications and components. MEF provides a way for host application to consume external extensions without any configuration requirement.