NLib

As the name suggests, NLib is a library designed to help extend .NET Framework with more classes. Generally speaking, extension methods can come in handy when developing programs using .NET Framework. Even though it was initially designed to work with .NET Framework, according to the developer, it should be able to work just fine with other libraries as well.
For starters, they can cut down on the time needed to add a new class, as extension enables the use of classes that are already referenced and compiled. A classic example of when extension methods can be helpful is when a very specific and small task is needed and that is applicable to an already compiled class. In addition, the said task will be required on more than one occasion.
In this example, spares developers the trouble of having to modify the original class just to add a new method for the purpose of solving something that is not included. In other words, extensions can add functions to the class without subclassing. The main advantage here is that the new function class can be added even when you do not have the original implementation of the said class. As previously mentioned, this works with both classes and extension methods.
   

System requirements