Calculus is the world's most advanced collections class library. It is written in C# (Calculus.dll) and this makes it available to C++, Visual Basic and Java programmers. The algorithms were developed by the author in C# in 2006. Since it is more than 10 years since their development, the classes are well tested and extremely stable. If C++ is included, these classes date back to 1989. If C and Pascal are included, these concepts date back to 1987.

Calculus contains an ordered set class which is of fundamental importance. Additionally, many multicollections are present in Calculus which cannot be found anywhere else. Many of these classes are critical to applications.

The Calculus Array class has many uses in operating system theory.

The Calculus Tree class required new interfaces for .Net. From this it is clear that Calculus is the first class library to define a tree class. That is, the very definition of what is meant by a binary tree class is exposed by Calculus.

The now famous STL map class has its equivalent in Calculus. It is the class Dictionary. This is a very large, high performing class of extreme importance. Some people rate dictionaries as the most important class in programming. In Calculus, Maps are different from Dictionaries. The Dictionary class is ordered whereas Maps are unordered.

This volume presents the class definitions of the classes contained in the Calculus.dll assembly. Each class contains:

- constructors,
- properties,
- operators,
- methods and
- a description.

The volume (as at the front page)
is a class __reference__.
Also present is a class guide, which explains
how to use the classes.