Question

jQuery uses this pattern. Essentially it involves every method returning a reference to the same object on which the method was called.

myClassInstance
    .DoMethodA()
    .DoMethodB()
    .DoMethodC()
    .CleanUp();

What’s this design pattern called?

UPDATE
The accepted answer is correct, and here is the link to the wikipedia entry for it – less informative than the link provided in the answer though 😛
http://en.wikipedia.org/wiki/Method_chaining

Answer 1

It is called method chaining.